With his approval ratings dented by his entanglement in the Middle East, Trump's hotly anticipated trip to China - the first by a US president to America's main strategic rival since his last visit there in 2017 - has taken on added significance.
Joining him on the trip are a group of chief executives looking to resolve issues with China, including Elon Musk and Nvidia's Jensen Huang, a late addition.
Trump has said his first request to Xi will be to "open up" China to US industry.
Kicking off the pomp-filled two-day summit, Trump was greeted by Xi on the red carpet outside the imposing ceremonial building on Thursday, with the leaders shaking hands and smiling warmly.
A brass band played the national anthems before the presidents strolled past rows of military honour guard and children waving flowers and US and Chinese flags, with Trump occasionally patting Xi on the back.
The power dynamic has shifted since Trump's last visit to Beijing when China went out of its way to lavish Trump and buy billions in US goods, said Ali Wyne, senior adviser for US-China relations at International Crisis Group.
Back then "China was trying to persuade the United States of its growing status ... This time around it's the United States, unprompted, of its own volition, that is acknowledging that status," Wyne said, pointing out Trump revived the term 'G2', referring to a superpower duo, when he last met Xi on the sidelines of an APEC meeting in South Korea in October.
This week's meetings will provide plenty of face time between the leaders: they are scheduled to hold talks at The Great Hall of the People, tour the UNESCO heritage site Temple of Heaven and attend a state banquet on Thursday, before taking tea and lunch together on Friday, according to the White House.
Trump enters the talks with a weakened hand. US courts have hemmed in his ability to levy tariffs at will on exports from China and other countries.
The Iran war has also boosted inflation at home and escalated the risk that Trump's Republican Party will lose control of one or both legislative branches in November's midterm elections.
Though the Chinese economy has faltered, Xi does not face comparable economic or political pressure.
Nevertheless, both sides are eager to maintain a trade truce struck last October in which Trump suspended triple-digit tariffs on Chinese goods and Xi backed away from choking global supplies of rare earths, vital in making items from electric cars to weapons.
They are also expected to discuss forums to support mutual trade and investment and dialogue on AI issues.
Washington looks to sell Boeing airplanes, farm goods and energy to China to cut a trade deficit that has long irked Trump, while Beijing wants the US to ease curbs on exports of chipmaking equipment and advanced semiconductors, officials involved in the planning said.
Aside from trade matters, Trump is expected to encourage China to convince Tehran to make a deal with Washington to end the conflict.
US Secretary of State Marco Rubio told Fox News aboard Air Force One that it was in China's interest to help resolve the crisis as many of its ships are stuck in the Gulf and a slowdown in the global economy would hurt Chinese exporters.
For Xi, US arms sales to Taiwan, the democratically governed island claimed by China, will be a top priority.
China reiterated on Wednesday its strong opposition to the sales, with the status of a $US14-billion ($A19 billion) package awaiting Trump's approval still unclear.
With AP
