WASHINGTON — Three days of U.S.-Chinese talks aimed at ending a tariff battle wrapped up Wednesday in an optimistic atmosphere, with President Donald Trump saying they were “going very well!”

A statement from the Office of the U.S. Trade Representative did not characterize the tone of the talks or say what would happen next, noting only that the U.S. delegation would await “guidance on the next steps” after reporting back to Washington

The U.S. statement said the negotiations dealt with the need for any deal with China to be “subject to ongoing verification and effective enforcement” — a comment that reflects U.S. frustration that the Chinese have failed to live up to past commitments.

The U.S. also said the negotiations “focused on China’s pledge to purchase a substantial amount of agricultural, energy, manufactured goods and other products and services from the United States.” Trump has complained repeatedly about the U.S. trade deficit with China.

Stocks surged on optimism that the talks in Beijing will be followed up with discussions between higher-ranking U.S. and Chinese officials. Investors were encouraged that talks planned for two days were extended to three.

“We can confidently say that enough progress was made that the discussions will continue at a higher level,” said Craig Allen, president of the U.S.-China Business Council.

The talks that started Monday were the first face-to-face meetings since Trump and his Chinese counterpart, Xi Jinping, agreed Dec. 1 to suspend further action against each other’s imports for 90 days while they negotiate over U.S. complaints that Beijing steals or pressures companies to hand over technology.

Washington wants Beijing to change its plans to use government support to make Chinese companies world leaders in robotics and other technologies.