President-elect Donald Trump waves to supporters during a rally in Grand Rapids, Mich., on Dec. 9. (Paul Sancya/AP)

President-elect Donald Trump said Monday that his businesses will do “no new deals” during his time in the White House, expanding on a pledge to separate his private finances and public power but raising new worries about long-standing conflicts of interest.

In late-night tweets Monday, Trump said he would leave the management of his real estate, licensing and other businesses to his sons Donald Jr. and Eric and company executives before his inauguration.

“Even though I am not mandated by law to do so, I will be leaving my busineses [sic] before January 20th so that I can focus full time on the Presidency. Two of my children, Don and Eric, plus executives, will manage them. No new deals will be done during my term(s) in office,” Trump tweeted.

Trump had pledged last month that he would host a media event Thursday explaining his next business moves, but his representatives said Monday that the event was postponed until next month. In a tweet, Trump said, “I will hold a press conference in the near future to discuss the business, Cabinet picks and all other topics of interest. Busy times!”

President-elect Donald Trump tweeted on Dec. 12, that he plans to hand over control of his businesses to his sons before the inauguration, and pushed back a scheduled news conference on how he will handle his business conflicts. (Video: Reuters / Photo: AP)

Ethics advisers said the “no new deals” pledge amounted to a “baby step” toward freeing Trump from a potential vulnerability during his time in office. But they said it would not be enough to combat the many entanglements already raising worries about presidential independence and decision-making.

“Every day there are going to be new negotiations, new terms, new transactions within the existing businesses,” said Norm Eisen, a chief White House ethics lawyer for President Obama.

“There's going to be a lot of major dealmaking inside existing projects. Even his [new Trump International Hotel in Washington] requires constant renegotiation between him and the United States,” Eisen added. “The notion of no new deals makes no sense whatsoever.”

Even with the new pledge, Trump's businesses will likely offer an easy target for the president-elect's opponents in Congress. Rep. Elijah E. Cummings of Maryland, the ranking Democrat of the House Committee on Oversight and Government Reform, said Tuesday that “the idea that Mr. Trump won’t do any future deals completely misses the point.”

“He already has a web of global entanglements that has to be addressed,” said Cummings, who is hosting a bipartisan forum Wednesday at the Capitol to discuss Trump's conflicts. “Giving his kids control of the business is not going to fix this. He seems to be in denial, and that may be why he canceled his press conference.”

Requests for more details from Trump representatives were not returned Tuesday. But Trump spokeswoman Hope Hicks told The Washington Post on Monday that “the president-elect has been focused on putting a team in place to enact real change starting on Day One.”

“With so many iconic properties and successful entities, moving the announcement to January ensures the legal team has ample time to ensure the proper protocols are put in place so his sole focus will remain on the country and achieving his ambitious agenda with the help of the world-class Cabinet he has built,” Hicks said.

Trump has said only that he would leave the management of his company but keep his ownership, potentially ensuring that he will retain a financial stake in the company's performance, even as he avoids the day-to-day operations. On “Fox News Sunday,” Trump said he's “not going to have anything to do with the management,” adding, “I’m not going to be doing deals at all.”

But the Office of Government Ethics, which advises public officials on how to avoid dangerous entanglements, says the only way Trump could truly avoid conflicts would be for him to fully divest from his companies. Leaving it in the family wouldn't be enough.

“Transferring operational control of a company to one's children would not constitute the establishment of a qualified blind trust, nor would it eliminate conflicts of interest,” OGE Director Walter Shaub wrote to to Sen. Tom Carper (D-Del.) in a letter released Tuesday.

The “no new deals” pledge could prevent new real estate partnerships from flourishing between the Trump Organization and investors across the country and overseas.

But Trump already holds the reins to a broad network of business interests, including more than 500 companies across the United States and with ties to at least 18 foreign countries, according to an analysis by The Post of Trump financial disclosures released in May.

The pledge also does little to tackle an issue of bipartisan concern: the hundreds of millions of dollars in debt Trump and his companies owe to lenders, including big banks in China and Germany. Those debts, ethics advisers said, could influence his political commitments or fuel questions about his policies.

The core revenue stream of Trump's real estate and licensing business has for years thrived on new deals: development partnerships, branding agreements and other lucrative arrangements based on the leasing of the Trump name to merchandisers and investors.

Many of Trump's existing business holdings could depend on new deals to stay afloat, including deals with banks to refinance loans or with companies leasing space in Trump properties. Even with a “no new deals” pledge, ethics advisers said, those established projects could still provide a channel for those seeking to curry favor with the Trump White House or influence political outcomes.

There is no law that would force the president to sell off his business interests or seclude them in a blind trust, run by an independent overseer with unimpeachable control. But every president over the past 40 years has followed a tradition of drawing a line between the Oval Office, their families and their financial interests.

Either way, it could prove difficult for Americans outside the companies to ensure they stick to the “no new deals” pledge. Trump's private businesses have traditionally shared very little about their debts, partners, active deals and potential other corporate entanglements. The scant information that is made public is not reviewed by third-party auditors, who could verify the results.

Trump's spokesman said last week that the businessman had sold all of his company stock in June, a move that would have zeroed out a portfolio of shares worth as much as $40 million in recent months. But Trump representatives have given no proof of the sale or other details, including why he sold the shares. Trump will not be required by law to file another personal financial disclosure until May 2018.

Many of the companies remain a mystery. During Trump's presidential campaign, he filed registrations for eight companies with names suggesting a hotel deal in Jiddah, the second-biggest city in the oil-rich kingdom of Saudi Arabia, which Trump has said he “would want to protect.”

Four of those companies were dissolved last year. The other four remained active until they were dissolved Nov. 15, a week after Trump's electoral victory, according to a state official in Delaware, where the companies were filed. Trump representatives did not respond to requests for more details about the potential deal, or why the companies were dissolved.

Trump's tweets did not reference his daughter Ivanka, one of the most prominent executives at the Trump Organization. She is expected to distance herself from the business and advise her father; she and her brothers have served on the Trump transition team's executive committee, helping solidify key appointments.

Trump's insistence that his heirs and executives will continue to run the company, advisers said, could still invite scandal or lead to potential constitutional violations, because the business could retain its name-brand ties to the presidency.

“While his sons present the most acute problem, the important part of a blind trust really is that an independent third party runs the company. His executives still have ties to him, or are known to have ties to him, and that could be a conduit for improper influence,” Eisen said. “A lot of quids are going to be thrown at them. How long until a quo comes back?”

Tom Hamburger contributed to this report.