Pro-China demonstrators rally in Hong Kong on June 30 as the city marks the 20th anniversary of the city's handover from British to Chinese rule. (Damir Sagolj/Reuters)

Call it President Trump’s hamburger diplomacy.

On Friday, U.S. Ambassador Terry Branstad, Agriculture Secretary Sonny Perdue and a clutch of American cattlemen in 10-gallon hats gathered at a chic hotel in Beijing to sip champagne and celebrate the return of U.S. beef after 14 years.

The servings of American cattle at the event were a product of the 100-day plan negotiated when Trump and Chinese President Xi Jinping met at Trump’s Mar-a-Lago resort in April. Trump’s message then was: You help us rein in North Korea, and the rest is on the table in trade talks.

But the message is changing — and so is the mood.

Just hours before the ceremonial return of U.S. beef, the White House announced two moves that could spoil the U.S.-China party: the latest round of arms sales to Taiwan and fresh sanctions on North Korea that target a Chinese bank.

U.S. flags and branding are seen on American beef samples during a promotional event in Beijing on June 30, 2017. (Fred Dufour/AFP/Getty Images)

China quickly denounced the Taiwan weapons deal as a slap at Beijing’s sovereignty and framed the sanctions as disruptive overreach by Washington.

Both moves show the Trump administration coming to terms with the challenges of getting China to tighten the screws on its client state North Korea, where the regime of Kim Jong Un depends on Beijing as its lifeline.

As Trump tweeted June 20, “It has not worked out.”

Clearly, Trump is frustrated. And now, so are the Chinese.  

At a news briefing Friday, Lu Kang, a spokesman for the Chinese Foreign Ministry, said Beijing has launched “solemn representations” with the United States over the arms sale. He also spoke out about the sanctions, warning of consequences to U.S.-China ties.

The “U.S. wrong moves go against the consensus achieved at Mar-a-Lago,” he said.

(Jason Aldag/The Washington Post)

The Chinese Embassy in Washington said in a statement: “The Chinese government and Chinese people have every right to be outraged” over Taiwan.

The island has received U.S. arms for more than three decades, but the current Chinese anger appears amplified by feelings that Trump might have taken a difference course after his talks with Xi.

Despite all the talk of cooperation, China and the United States clearly disagree on how to pressure North Korea to retreat from its nuclear weapons program and ballistic missile development. China has repeatedly stressed that it opposes unilateral moves, saying sanctions should be handled by the United Nations, not the United States.

By moving ahead with fresh sanctions, the United States has done what Beijing feared. 

“Trump may have misunderstood how much China can affect North Korea,” said Ni Feng, deputy director of the Institute of American Studies at the Chinese Academy of Social Sciences.

“He might have had some unrealistic expectations,” he said, “which may have led to some disappointment.”

The sanctions announced by Treasury Secretary Steven Mnuchin aim to cut off China’s Bank of Dandong from U.S. financial markets in an effort to block millions of dollars in transactions that funnel money into North Korea.

U.S. citizens also will be prohibited from doing business with two Chinese business executives accused by Washington of establishing and running front companies on behalf of North Korea, and with Dalian Global Unity Shipping, which is accused of transporting 700,000 tons of freight annually between China and North Korea.

Mnuchin insisted that the United States is “in no way targeting China with these actions” and that U.S. officials “look forward to continuing to work closely with the government of China to stop the illicit financing in North Korea.”

Beijing does not buy that. China’s ambassador to the United States, Cui Tiankai, said China opposed any U.S. use of domestic laws to impose “long-arm jurisdiction,” state media reported Friday.

The arms sale adds an even bigger wrinkle.

For Taiwan, news of the sale comes as a relief after significant back and forth under Trump.

When the United States opened diplomatic relations with China in 1979, it broke off formal ties with Taiwan. Under the one-China policy, Washington acknowledges China’s position that there is only one Chinese government but does not endorse it, and it maintains strong unofficial relations with Taiwan.

Not long after the U.S. presidential election, Trump surprised many, including China, by taking a call from Taiwanese President Tsai Ing-wen and later suggesting on Twitter that he might change the U.S. position on Taiwan. Then he changed course, moving to reassure Beijing.

The arms sale is worth $1.4 billion and includes technical support for early-warning radar, anti-radiation missiles, torpedoes and components for SM-2 missiles, a surface-to-air defense system.

While the deal was the first such sale to Taiwan since Trump took office, it marks a continuation of U.S. policy.

“This package appears to be unchanged since last year under Obama,” said Bonnie S. Glaser, a senior adviser for Asia at the Center for Strategic and International Studies in Washington.

Still, she said, the sale “demonstrates that the Trump administration will not forgo necessary steps to bolster Taiwan’s defense to get China’s cooperation on North Korea.”

Simon Denyer in Hong Kong and Shirley Feng and Yang Liu in Beijing contributed to this report.