The two world leaders are scheduled to meet in Argentina on the sidelines of the G-20 summit on November 30 and December 1.
The economies of both countries are highly complementary, and both people benefit from the bilateral cooperation, he said, adding that various problems may occur in the economic and trade cooperation.
Though China's overall economic status is stable, "uncertainty in our country's economic development has clearly increased, downward pressure has grown, and companies are facing more difficulties", said Mr Xi, according to the official Xinhua news agency.
The direct talks were the first between the two leaders to have been reported since May.
The last round of trade talks with China ended in August with no concrete steps toward reaching a deal.
A Justice Department indictment targeted two companies based in China and Taiwan and three individuals, saying they conspired to steal trade secrets from USA semiconductor company Micron Technology Inc.
A key point of contention for the USA has been its allegations that China has engaged in widespread intellectual property theft. "He is just saying if the Chinese respond and improve, and they deliver the goods - technology, ownership, IP, tariffs - and they start playing by the rules, then yes tariffs could be removed", he said.
Despite the promise offered by the Trump-Xi telephone call, the level of tension between the two nations was demonstrated just hours after it ended when the USA filed charges against Chinese technology firm Fujian Jinhua Integrated Circuit Co and its Taiwanese partner.
Trump says of China: "I know they want to make a deal". We're getting closer to something.
The ministry said Friday the two leaders agreed to "strengthen economic exchanges" but gave no indication whether they made any progress on settling an escalating tariff war over Beijing's technology policy.
Meeting a group of Republican lawmakers in Beijing, China's Li noted the China-U.S. relationship's "ups and downs" over the past four decades.
"We do hope that China and the United States will meet each other halfway and work together in the spirit of mutual respect and equality", Li told Trump's fellow Republicans. While he said the delegation wished to discuss trade, he offered no specifics in opening remarks before reporters were ushered from the room.
He, however, warned that he had billions of dollars worth of new tariffs ready to go if a deal did not materialise.