Afterward, Trump described the meeting as "excellent" and said the U.S. and China are "back on track" but that "negotiations are continuing."
The meeting between the two leaders at the G-20 summit is their first in seven months, although the two reportedly saw each other at a dinner for the Group of 20 leaders, where Trump said much was accomplished.
Trump and Xi were expected to focus on issues including trade and a dispute over Huawei Technologies.
"We've had an excellent relationship," Trump said to Xi at the beginning of the meeting, "but we want to do something that will even it up with respect to trade."
Trump told reporters he thought they would have a “very productive” meeting. “I think we can go on to do something that will be truly monumental and great for both countries," he added.
Xi said he felt both the U.S. and China benefit from cooperation and lose with confrontation. "Cooperation and dialogue are better than friction and confrontation," he said.
Trump has already put tariffs on $250 billion in Chinese imports and has threatened to tax an additional $300 billion. China retaliated with its own tariffs on American exports.
After the meeting with Xi, Trump has another with Turkish President Recep Tayyip Erdogan.
The Associated Press contributed to this report.
This is a developing story. Check back for updates.