The two leaders and their wives attended a state dinner, a black-tie affair of sesame-crusted sea bass and a guest list heavy with tech CEOs.
Outside the gate, a group of loud protesters shouted slogans like "China out of Hong Kong" that were clearly audible to the leaders as they posed for pictures on the red-carpeted White House steps.
In his dinner toast, Trump said he and Xi "both understand we represent different systems but the ties between our people endure and we've never gotten along better."
Xi said he and Trump had in-depth discussions and reached "common understanding on many issues" that provided "new strategic guidance for China-US relations." He did not elaborate.
"China and the United States must act as responsible major countries," he said, calling for "a new approach for major countries to get along with each other."
The guest list for Thursday's state dinner included CEOs such as Apple's Tim Cook, Amazon's Jeff Bezos, Alphabet's Sundar Pichai, OpenAI's Sam Altman, Tesla's Elon Musk and Nvidia's Jensen Huang.
Xi noted in his toast that "President Trump has pledged to make America great again" and that "China is committed to achieving great national rejuvenation."
"These two goals are both ambitious and can surely be mutually reinforcing," he said.
During a bilateral discussion in the afternoon, Xi urged the US to oppose "Taiwan independence," according to a readout from the official Chinese news agency - addressing one of the thorniest issues between the two countries.
The White House has not yet provided its own summary of the talks.
Xi had been expected to press Trump this week to halt arms sales to Taiwan. Following his visit to China in May, Trump said he was holding in abeyance an arms package to Taiwan worth some $US14 billion and called it a "very good negotiating chip."
That move left some US allies in Asia and even some of Trump's fellow Republicans concerned that he may be tempted to soften Washington's support for Taipei in exchange for economic wins. China claims democratically governed Taiwan as its own territory and has not ruled out using force to gain control over the island.
The summit between the two leaders came shortly after Trump forcefully defended his use of military power in a speech at the UN earlier this week, suggesting he could "annihilate" Iran.
He took a strikingly different tone with Xi on Thursday, reflecting a power balance that has shifted toward the Chinese leader after a trade war that ended with a US climbdown on tariffs.
In remarks after Xi's arrival on Thursday, Trump said the two powers had made strides on trade since his trip to China in May.
Somewhat more pointedly, Xi said the two countries' interests were deeply intertwined and competition between them should be a "healthy one."
US companies were welcome in China, he said, adding that he hopes "Chinese companies are treated fairly here in the United States."
The summit, Xi's first visit to Washington in more than a decade, is the second meeting this year between the leaders of the world's two biggest economies.
For Trump, who relishes ceremony and prizes his ties with powerful leaders, the visit is as much a matter of national prestige as an opportunity for high-stakes diplomacy.
But Trump and Xi's remarks were not carried live by any US television networks, which refused to provide footage in protest of the White House's ban of CNN, MS Now and Politico.
During his comments on Thursday, Xi said both countries must "ensure that the development of AI is always under human control."
Analysts say intense competition between the two powers in AI is likely to limit the scope for anything beyond symbolic agreements.
with Reuters and AP
