As the two leaders toured the National Archives and shared tea in the White House Red Room, Iran emerged as a key point of friction. US Ambassador to China David Perdue told CNBC that Mr Trump made clear during the talks that Chinese help for Tehran would not be tolerated.
"We made it very clear to them weeks ago that, you know, any help that they would give Iran, whether it be direct or indirect, whether it be intelligence or parts or military equipment, was totally unacceptable," Mr Perdue said. "President Trump made that very clear again."
Beijing has denied US allegations of helping Iran's leaders during the conflict. Asked whether he expected progress on reopening the Strait of Hormuz, Mr Trump replied: "I think we're going to do great."
Mr Trump described the summit between the leaders of the world's two largest economies as having produced great strides, despite a lack of concrete results. "I think our farmers are going to be happy," he said, without elaborating. "America is very happy about this visit, and I'm sure China is very happy also."
US Trade Representative Jamieson Greer said details of the limited agreements on trade would be released on Monday, including exemptions on exports to China of agricultural products and medical devices and imports of consumer and non-sensitive goods.
Mr Xi said the US-China relationship had developed into a constructive one of "strategic stability on the basis of respect, fairness and reciprocity," and that the two leaders would meet twice more this year at the APEC summit in China and a G20 summit in Miami.