WASHINGTON, D.C.: U.S. President Donald Trump and Chinese President Xi Jinping ended a three-day summit on September 25 with a ceremonial visit to the National Archives and talks over trade, artificial intelligence and other issues, but without major breakthroughs on their biggest disagreements.

The two leaders drank tea at the White House before traveling by limousine to the National Archives, where they viewed the U.S. Declaration of Independence, the Constitution and the Bill of Rights.

Trump said the talks had produced benefits for American farmers but did not give details. He also described the visit positively, saying, "America is very happy about this visit, and I'm sure China is very happy also."

Xi said the relationship between the world's two largest economies had become more constructive. He described it as a relationship based on strategic stability, respect, fairness and reciprocity.

The summit included military flyovers, ceremonial events and a state dinner. However, major differences remained over trade, artificial intelligence, Taiwan and China's relationship with Iran.

U.S. Trade Representative Jamieson Greer said details of the limited trade agreements reached during the visit would be released on September 28.

Trade Truce Extended

One clear result was an agreement to extend the existing U.S.-China trade truce by two months. The truce had been due to expire on November 10, giving both sides more time to negotiate a larger trade agreement.

Greer told CNBC that Washington and Beijing had also agreed to exemptions for certain key goods involved in their trade disputes. These included U.S. agricultural products and medical devices sold to China, as well as Chinese consumer and other non-sensitive goods imported into the United States.

Trump highlighted progress through the bilateral trade mechanism, saying the talks had resulted in greater market access for American farmers and ranchers. Both leaders also identified artificial intelligence as an area where the two countries could continue discussions.

Trump said on social media that he and Xi planned to meet twice more before the end of the year. One meeting is expected in China in November during the Asia-Pacific Economic Cooperation forum, while another is planned for Miami in December during a G20 summit.

Iran and Taiwan

Iran was also discussed during the summit. Trump said he and Xi had talked about Iran but did not provide details. China has rejected U.S. allegations that it has helped Iranian leaders during the conflict that began with Trump's attacks in February.

U.S. Agriculture Secretary Brooke Rollins said Trump had told Xi that any direct or indirect support for Iran was unacceptable. She said China had assured the U.S. it would not provide such support.

Taiwan remained another major issue for Xi.

China claims Taiwan as part of its territory, although the island has been democratically governed for decades. Xi has sought a stronger public statement from Trump that Washington opposes Taiwan's independence. The United States has traditionally said it does not support Taiwan independence, while maintaining its own policy of strategic ambiguity.

Xi has also sought an end to U.S. arms sales to Taiwan.

The United States does not have formal diplomatic relations with Taiwan, as with most countries. However, Washington is Taiwan's main international security partner and U.S. law requires it to provide the island with defensive equipment.

U.S. allies in Asia closely watched Trump's comments on Taiwan after Xi's visit. By Friday afternoon, Trump had not made a significant new statement on the issue.

After his May meeting with Xi, Trump said he was holding back a second arms package for Taiwan worth about US$14 billion. He described the package as a negotiating tool. His administration had previously approved an $11 billion arms package for Taiwan in December.