Mike Bloomberg was presiding over his inaugural Bloomberg New Economy Forum in Singapore in 2018 when, to the surprise of some in the audience, he gushed about one of China’s top government officials.

Vice President Wang Qishan was “the most influential political figure in China and in the world,” Bloomberg said, breaking from a prepared text that had said the keynote speaker was “one of” the most influential. Bloomberg noted that he and Wang had first met at Bloomberg’s home 15 years earlier, when he was mayor of New York and Wang was mayor of Beijing, and he praised the vice president for helping lead China “through a period of extraordinary growth.”

Then in September, amid mass pro-democracy protests in Hong Kong and human rights activists decrying China’s imprisonment of Muslim minorities, Bloomberg seemed to go out of his way to defend Beijing, saying in a television interview that President Xi Jinping “is not a dictator.” Bloomberg said Xi “has to satisfy his constituents or he’s not going to survive.” Pressed by the interviewer, Bloomberg said Xi “has a constituency to respond to . . . they really are responsive.”

If President Trump’s unprecedented decision to retain ownership of his global real estate business has tested the limits of America’s ethics laws and traditions, sparking lawsuits and allegations of influence by foreign interests, a Bloomberg presidency could present a whole new level of overseas entanglements — with China as a prime example.

Tensions have grown between Washington and Beijing in recent years amid trade disputes, clashes over democracy and human rights, and disagreements over China’s efforts to expand its influence around the world. Yet Bloomberg, who is spending tens of millions of dollars of his own money to compete for the Democratic presidential nomination, has deepened his entanglements with that key U.S. adversary — forging close financial ties there while showering praise on the Communist Party leaders whose goodwill is required to play a role in that fast-growing market.

The billionaire, whose core business sells financial information to investors, has led efforts since 2015 to make it easier for U.S. companies to trade in Chinese currency, a move embraced by China’s largest banks. He expanded one of his company’s financial indexes, which could steer $150 billion into China while earning his firm an undisclosed amount in fees.

All told, mainland China accounts for 1 percent of Bloomberg LP’s revenue and Hong Kong for another 4 percent. Overall, Bloomberg LP’s $10 billion in annual revenue far surpasses that of the Trump Organization, which was at least $435 million in 2018, according to Trump’s financial disclosure.

Trump’s ownership of hotels, including one near the White House, has been challenged as a violation of a constitutional provision that forbids a president from taking payments from foreign governments. Bloomberg’s business is far broader, interwoven into the financial fabric throughout the world.

While Bloomberg has stepped aside from running his privately held company as he runs for president, he has maintained his 88 percent ownership stake. If elected, a spokesman said, Bloomberg would either put the company in a blind trust or sell it. It is not clear whether putting his business in a blind trust would negate questions about a conflict of interest because Bloomberg would know the main asset of the trust is his company.

If Bloomberg were elected president, he would immediately have to deal with the same Chinese officials he worked with closely as the chief executive of his business — but in his new role, he would be embroiled in the trade war and face questions about how to deal with China’s human rights violations and its handling of pro-democracy protesters.

Kyle Bass, a hedge fund manager whose past investments once included a bet that Chinese currency would fall in value, said voters inevitably will ask whether Bloomberg feels beholden to China.

The Chinese government, Bass said, “has enormous financial leverage over anyone who does business with them, and so when Mike Bloomberg does interviews and says Xi is not a dictator, I believe Mike Bloomberg is blinded by his wallet.”

Bass stressed that he believes Bloomberg is the “most capable” of all the presidential candidates but said “his biggest weakness and biggest vulnerability is on China.”

“It is a problem for a president, a public official, to continue to own business interests in countries that have been designated by the U.S. government as a strategic competitor,” said Andrew J. Nathan, a China specialist and professor of political science at Columbia University.

Bloomberg declined an interview request. His spokesman, Jason Schechter, said in a written response to questions that, “As President, Mike will speak up about areas where we have profound differences with China, including on human rights, democratic freedoms and trade.” Schechter said Bloomberg supports sanctions against China in response to “gross violations of human rights against the Uighurs.”

In addition, Schechter said Bloomberg believes that “the Chinese have taken advantage of the global trading system” in ways that hurt U.S. workers and that, as president, he would “address those problems.” The spokesman said Bloomberg would work cooperatively with China on issues of mutual concern such as climate change, adding that Bloomberg “will always say and do what he thinks is right for America, regardless of the impact on his business.”

A spokesman for the Chinese Foreign Ministry declined to discuss Bloomberg, saying, “China will not comment on specific individuals, enterprises or relevant business activities,” while adding that the country welcomed “all endeavors that contribute to ­China-U.S. friendship and cooperation.”

Ninth-richest person

Bloomberg is one of the world’s richest people, although that would not be known by examining the 500-person Bloomberg Billionaires Index. The company’s policy is not to cover itself, so Bloomberg himself “isn’t considered for this ranking,” the company says in a note about its methodology. Forbes magazine says Bloomberg is the world’s ninth-richest person, with a net worth of $55.5 billion.

Bloomberg’s wealth is partly derived from his company’s expansion far beyond its New York City roots. Bloomberg’s company opened offices in Beijing 25 years ago, selling its computer terminal and financial information subscriptions. Bloomberg has long held the view that a “growing Chinese economy is good for America,” as he wrote in a 2008 article in Newsweek. Bloomberg said that “we have a stake in working together to solve common problems, rather than trying to browbeat or intimidate the other into action.”

As Bloomberg has urged cooperation with China, questions have been raised about whether his news service has held back from publishing information that would offend the Chinese leadership, because of concern that the government would expel his employees.

At first, the company was praised for its willingness to produce tough reporting about the Chinese leadership. It won a prestigious Polk Award for its 2012 article about the family finances of Xi, who was then vice president. The company’s terminal sales in China declined, and the government imposed restrictions on Bloomberg News employees. Bloomberg’s website was blocked from being viewed in mainland China.

But the following year, after Xi was elevated to the presidency, a follow-up investigation was not published. The New York Times reported at the time that Bloomberg’s editors had refused to release the story as written because it would offend the Chinese leadership.

A Bloomberg manager was quoted as telling members of the Hong Kong bureau, “If we run the story, we’ll be kicked out of China.” A Bloomberg reporter suspected of leaking the information was suspended and left the company, joining the New York Times.

Bloomberg, who was then mayor of New York City, stressed at the time that he was not running Bloomberg LP and that his assets were in a blind trust. Still, he said Bloomberg’s editors had assured him they had not censored the information.

After returning to run the company in 2014, Bloomberg was asked by CNBC whether his news service had “muzzled” reporters. He responded: “In China, they have rules about what you can publish. We follow those rules. If you don’t follow the rules, you’re not in the country.”

Since then, Bloomberg has spent many hours with China’s leaders and the relationship has blossomed. While the company’s website is still blocked in China, as are other American media sites including The Washington Post’s, it is allowed to sell its terminals and subscription service and has expanded its operations in the country. About 200 of Bloomberg LP’s 20,000 employees work in mainland China and another 800 work in Hong Kong, the company says.

But the company’s presence in China is invaluable in ways that don’t show up in a balance sheet, enabling Bloomberg to provide economic data that is crucial for many subscribers around the world.

Parag Khanna, founder of the strategic advisory firm FutureMap and author of the book “The Future is Asian,” has written that Bloomberg’s company is “effectively the world’s largest private intelligence service,” which is particularly notable in the relatively opaque Chinese marketplace.

Subscribers around the world rely on Bloomberg-generated information to help them decide where and how to invest capital — a trove that is vital to China’s efforts to entice investment in the government’s bonds.

To meet that need, Bloomberg’s company in March 2018 announced that it would add 333 Chinese government bonds to its Bloomberg Barclays Global Aggregate Bond Index. That opened the way for tens of billions of dollars to flow from investment funds in the United States and elsewhere to four Chinese institutions that issue bonds, including the Chinese government and the China Development Bank.

It was a breakthrough achievement for Bloomberg LP — and China. Bloomberg’s company earns a licensing fee when investment firms use the index as the basis for their financial products. A Bloomberg spokesman declined to say how much revenue the company expects to collect in such fees.

By some estimates, investors are expected to pour some $150 billion into the Chinese bonds in the next couple of years. As a result, while Trump’s tariffs are taking effect, Bloomberg’s company is helping the Chinese economy, analysts said.

“Companies that control financial capital — pension funds and other asset managers — are the investors who have Bloomberg terminals and represent trillions of dollars of savings looking for high returns,” Khanna said. “Those are the investors that China is courting as it further opens its capital account to foreigners.”

David Tabaka, who analyzes global indexes for Burton-Taylor International Consulting, said the money flowing into China as a result of the index “is very important” to the country’s leaders. “It’s a net positive for them,” he said.

But the inclusion of Chinese bonds in the index has been criticized by those who object to the use of funds that may originate in the United States to support the communist country.

Bloomberg personally trumpeted the inclusion of Chinese bonds in the index, saying in a 2018 news release that it would “enhance access to the world’s third-largest bond market” and is “a testament to China’s firm commitment to financial reforms.”

Similarly, Bloomberg has devoted himself to making it easier for U.S. companies to do business in Chinese currency, chairing the Working Group on U.S. RMB Trading and Clearing, which includes many of the largest banks in the United States and China. He has cited the group’s work as evidence that China is opening its markets.

Opposes tariffs

Bloomberg’s effort to influence U.S.-China policy has been particularly evident on trade issues, making him one of the most vocal U.S. business leaders opposing tariffs on China’s exports. Bloomberg came to Washington in 2018 to announce that he would lead an effort against trade policies that he said would hurt the U.S. economy as well as “strain ties with nations around the world, including China, and we can’t let that happen.”

That put him sharply at odds with the efforts of Trump, who in September 2019 boasted that he had approved tariffs on more than $500 billion worth of Chinese goods in an effort to get the country to negotiate. (Trump recently announced the terms of a partial trade deal with China in which he canceled tariffs on $160 billion of those goods, halved tariffs on another $120 billion and left in place a 25 percent tariff on another $250 billion.)

Bloomberg also strengthened his ties to China in 2018 when he launched the inaugural meeting of the Bloomberg New Economy Forum. He envisioned it as similar to the World Economic Forum held annually in Davos, Switzerland. Bloomberg’s forum, he said at the time, would focus on “China as an emerging power and how we all work together.”

The first forum was slated to be held in Beijing, but the U.S.-China trade war, as well as an overlap with a separate economic meeting, necessitated that it be moved to Singapore. Some 400 business and political leaders were invited, with the keynote delivered by Wang, China’s vice president.

The event was considered a success by China, and in 2019, it was held in Beijing. Bloomberg was slated to oversee it once again, but he did not attend because it conflicted with his announcement that he was running for president.

Now that Bloomberg is a candidate, his decades of work in China and relationship with the Chinese leadership are drawing unprecedented scrutiny at a time of continuing tensions between the countries with the world’s two largest economies.

Among those awaiting an explanation for his statement that Xi is not a dictator are advocates for Uighurs, Kazakhs and other ethnic minorities who have been forced into internment camps and other facilities in the Xinjiang region.

“Mr. Bloomberg is completely wrong in saying that Mr. Xi is not a dictator and completely wrong in saying he is responsive,” said Louisa Greve, director of global advocacy for the Uyghur Human Rights Project, which estimates that 2 million to 3 million members of the ethnic group have been “detained or disappeared.”

Greve said that a series of Chinese moves, such as a measure adopted that enables Xi to be president for life, are classic signs of a dictatorship.

Some China experts said Bloomberg’s declaration that Xi is not a dictator stems from his understanding that the Chinese government works through various layers of committees and not by one person’s edict.

“When he is talking about how China works and not a dictatorship, I think he is just observing what he has seen over the years and throwing it out there without sucking up to the Chinese leadership,” said Peter Walker, author of “Powerful, Different, Equal: Overcoming the Misconceptions and Differences Between China and the U.S.”

“It is pretty gutsy of him, saying something positive or even neutral about China,” Walker said. “There are a lot of people who don’t want to hear that story. It is one that is so counter to the belief that the American model is the best model there is.”

Felicia Sonmez and Alice Crites contributed to this report.