"We're the two superpowers," Trump told reporters as he departed the White House on Tuesday.
"We're the strongest nation on earth in terms of military. China's considered second."
While Trump likes to project a sense of strength, the state visit occurs at a delicate moment for his presidency as his popularity at home has been weighed down by the US and Israel's war with Iran and rising inflation as a consequence of that conflict.
The president is seeking a win by signing deals with China to buy more American food and aircraft, saying he'll be talking with Xi about trade "more than anything else".
The Trump administration hopes to begin the process of establishing a "Board of Trade" with China to address differences between the countries.
The board could help prevent the trade war ignited last year after Trump's tariff hikes, an action China countered through its control of rare earth minerals. That led to a one-year truce last October.
But Trump comes to Beijing at a time when Iran continues to dominate his domestic agenda.
The war has led to the effective closure of the Strait of Hormuz, stranding oil and natural gas tankers and causing energy prices to spike to levels that could sabotage global economic growth.
The US president declared that Xi didn't need to help resolve the conflict, even though Iran's Foreign Minister Abbas Araghchi was in Beijing last week.
"We have a lot of things to discuss. I wouldn't say Iran is one of them, to be honest with you, because we have Iran very much under control," Trump told reporters.
The status of Taiwan also appears to be a major topic as China is displeased with U.S plans to sell weapons to the self-governing island that the Chinese government claims as part of its own territory.
Trump told reporters Monday that he would be discussing with Xi an authorised $US11 billion ($A15 billion) weapons package for Taiwan.
At the same time, Taiwan - as the world's leading chipmaker - has become essential for the development of AI, with the US importing more goods so far this year from Taiwan than China.
Trump has sought to use Biden-era programs and his own deals to bring more chipmaking to America.
But Trump was already portraying the trip as a success before he left White House grounds.
He openly mused about Xi's planned reciprocal visit to the US, lamenting that the ballroom under construction won't be completed in time.
"We're going to have a great relationship for many, many decades to come," Trump said of the US and China.
"As you know, President Xi will be coming here toward the end of the year. So that would be exciting. I only wish we had the ballroom finished."
