White House press secretary Sarah Sanders said Trump promised not to go through with a planned hike -- from 10 percent to 25 percent -- on $200 billion worth of Chinese products.
In exchange, Xi agreed to purchase a "very substantial" amount of agricultural, energy and industrial product from the United States.
"It's an incredible deal. It goes down, certainly -- if it happens, it goes down as one of the largest deals ever made," Trump told reporters aboard Air Force One on his trip back to Washington, D.C. "And it'll have an incredibly positive impact on farming, meaning agriculture, industrial products, computers -- every type of product."
Earlier in the evening, Larry Kudlow, the director of the National Economic Council under Trump, said the meeting went "very well."
China's state-run Xinhua News Agency reported that Xi said he was glad me meet Trump and was looking forward to sharing more views "on issues of common concern." Xi added that he believed cooperation was the best option for both countries.
Xi said earlier he believes the leaders of the world's two largest economies "have good visions for a healthy and stable development of China-U.S. relations as well as for the expansion of economic and trade cooperation."
The two countries have been locked in a trade war this year with both extending tariffs on items each country exports to the other.
A statement from Sanders said the two parties planned to complete negotiations in 90 days on U.S. concerns over intellectual property, non-tariff barriers, cyber theft and cyber intrusions.
Additionally, Xi, "in a wonderful humanitarian gesture," agreed to label fentanyl, an opioid, as a controlled substance. The move would make sales of the substance to the United States eligible for the maximum penalty in Chinese law.
"This was an amazing and productive meeting with unlimited possibilities for both the United States and China. It is my great honor to be working with President Xi," Trump said.