Just two months ago, President Trump and China’s leader, Xi Jinping, strolled together through a garden of the secretive leadership compound in the heart of Beijing, past rows of bright flowers and leafy plants.

The U.S. president toasted Mr. Xi as “my friend” at a state banquet during his visit. He declared that he had received a “magnificent welcome like none other” that had helped smooth the way to “fantastic trade deals.”

The stage was set, Mr. Trump said, for Mr. Xi to make a reciprocal state visit to Washington in late September.

But in a prime-time speech on Thursday night, Mr. Trump struck an overtly hostile note, accusing China of carrying out “the largest compromise of election data in history.”

Mr. Trump said he was releasing declassified documents that showed China had interfered in the election, though the actual material failed to reveal any new or potent information about Beijing’s efforts.

And U.S. intelligence assessments said there was no evidence China did anything to affect the outcome of the 2020 vote.

The question now is not whether there was anything substantial behind Mr. Trump’s accusations, but whether his remarks threw off the relationship he had been trying to establish with Mr. Xi.

Probably not, analysts say, given Mr. Trump’s persistent, gushing admiration of Mr. Xi over the years, his embattled foreign policy in other areas — namely, the Iran war — and the commercial leverage that China has over the United States.

Still, Mr. Trump’s speech showed how quickly he can put aside diplomatic goals to try to gain short-term advantage in domestic matters, even when it involves the world’s other superpower.

His casting of China as a villain in U.S. elections came as he was desperately trying to get an election regulation bill passed in Congress. He also evoked the boogeyman of China in his 2016 presidential campaign and again in 2020, when the pandemic hobbled his re-election chances.

The Chinese government appears to be taking Mr. Trump’s comments in stride. There was little coverage of his remarks in state news outlets, and a foreign ministry spokesman, Lin Jian, shared boilerplate comments when asked about the accusations.

“This is a false allegation and serious smear that has long been proven to be unfounded,” he said on Friday. “We urge the U.S. to reflect on its behavior, stop vilifying China and framing China for election purposes, and act in ways conducive to China-U.S. relations.”

That last line indicated that Chinese officials think Mr. Trump’s accusations were oriented toward domestic politics, and were not a harbinger of a policy shift.

Mr. Xi, rather than acknowledging Mr. Trump’s remarks, spent Friday at a forum in Shanghai laying out China’s vision for global cooperation and governance on artificial intelligence.

“Based on China’s low-level and rote response, I am confident they understand Trump’s comments are almost entirely about domestic U.S. politics,” said Ryan Hass, a former career diplomat and White House national security official who directs a China center at the Brookings Institution. “Count me skeptical that Trump’s speech will have lasting impact on the relationship, unless he goes well beyond where he left things last night.”

John Culver, a retired intelligence officer specializing in China, years ago examined the material presented by Mr. Trump on Thursday night. Mr. Culver said that “as with the disputed U.S. 2020 elections, Xi likely understands that Trump’s renewed claims — with no new evidence — reflect Trump’s low approval ratings and the prospect of deep Republican Party losses in the midterm elections.”

Asked for comment, the White House said only that plans for Mr. Xi to visit Washington in September were proceeding.

Discussion of the major issues around the summit is expected to take place next week when Secretary of State Marco Rubio travels to Manila, the capital of the Philippines. He has plans to meet with Wang Yi, China’s top diplomat, on the sidelines of an annual conference of Southeast Asian nations.

After meeting with Mr. Wang in Malaysia a year ago, Mr. Rubio said the two nations were seeking “strategic stability.” Chinese officials at the Beijing summit then got Mr. Trump to agree to a framework of “constructive strategic stability.”

At the forum in Shanghai, Mr. Xi said that China as a superpower would ensure developing nations had proper access to advances in A.I., and that together they would share the technology to avoid “new historical injustices.”

“The juxtaposition of Trump’s and Xi’s speeches makes for a truly alarming split screen — China planning forward and presenting a collaborative front, America looking backward and appearing highly conspiratorial and polarized,” said Julian Gewirtz, a China historian who worked at the White House National Security Council and the State Department in the Biden administration.

Mr. Gewirtz added that Mr. Xi’s words about injustices, while vague, carried “a profoundly appealing message to many countries around the world that fear the Trump administration will capriciously cut off their access to American A.I. systems.”

That has been the pattern throughout the second Trump administration when it comes to the United States and China: Mr. Xi, the world’s most powerful autocrat, voicing global goals, while Mr. Trump talks about his obsessions and grievances.

Mr. Xi has picked up on that, and has deployed flattery at times to try to ensure that at least personal relations with Mr. Trump remain stable. At the state banquet in Beijing on May 14, over courses of crispy beef ribs, roasted Peking duck and tiramisu, Mr. Xi said in a toast that “the great rejuvenation of the Chinese nation and making America great again can go hand in hand.”

Instead of rejecting Mr. Trump’s signature phrase and movement — one that blames China for the downfall of U.S. manufacturing — Mr. Xi has appropriated it for his diplomatic aims.

Mr. Xi has reason to be confident. Last year, when Mr. Trump tried to escalate his trade war with China, Mr. Xi retaliated by moving to cut the United States off from supplies of processed rare earth minerals, over which China has a monopoly. Mr. Trump backed down, and has since tried to improve relations.

On Friday, the Chinese government said it welcomed the expiration of an order issued by Mr. Trump in 2020 that stripped Hong Kong of its special trade status with the United States. Mr. Trump issued the order after China imposed a harsh national security law on Hong Kong and quashed peaceful protests, moves that angered some of his aides.

But Mr. Trump rarely talks about human rights or democracy, and his efforts to hold a series of meetings with Mr. Xi this year are his priority now. Mr. Trump has always been excited by diplomatic pageantry with world leaders.

To ensure the meetings go smoothly, Mr. Trump has decided to halt final approval of a package of weapons to Taiwan valued at $14 billion, despite the fact the Congress has endorsed the sales.

Yet Chinese officials do not assume that any fundamental change to the relationship is taking place, no matter what remarks the U.S. president makes, said Yun Sun, a scholar at the Stimson Center in Washington. They still view the United States and China as engaged in a long-term competition, with the 20th-century superpower in decline and the Asian nation taking its place.