Deputy US Trade Representative Jeffrey Gerrish (C) leaves a hotel with his negotiation team for the second day of talks in Beijing on January 8, 2019.

China's Foreign Ministry said Wednesday that its trade talks with the United States had concluded, and that results would soon be released.

The length of the negotiations, which extended into an unexpected third day, suggests the serious nature of the discussions, the ministry said.

Asian stocks jumped after the talks were extended for an unscheduled third day, fueling optimism that the world's largest economies can strike a trade deal to avoid an all-out confrontation that would severely disrupt the global economy.

Ted McKinney, U.S. Under Secretary of Agriculture for Trade and Foreign Agricultural Affairs, addressed the negotiations earlier in the day to reporters at the delegation's hotel, saying "I think they went just fine."

"It's been a good one for us," he said without elaborating.

This week's meetings are the first face-to-face talks since U.S. President Donald Trump and Chinese President Xi Jinping agreed in December to a 90-day truce in a trade war that has roiled global financial markets.

Originally scheduled for Monday and Tuesday, the negotiations were extended by a day amid signs of progress on issues including purchases of U.S. farm and energy commodities and increased access to China's markets.

However, people familiar with the talks told Reuters on Tuesday that the two sides were further apart on Chinese structural reforms that the Trump administration is demanding in order to stop alleged theft and forced transfer of U.S. technology, and on how Beijing will be held to its promises.

If no deal is reached by March 2, Trump has said he will proceed with raising tariffs to 25 percent from 10 percent on $200 billion worth of Chinese imports, at a time when China's economy is slowing significantly. Beijing has retaliated in turn to U.S. tariffs.

But as meetings wound down in Beijing on Tuesday evening, Trump tweeted: "Talks with China are going very well!"

The U.S. team is led by Deputy U.S. Trade Representative Jeffrey Gerrish, and includes under secretaries from the U.S. Departments of Agriculture, Commerce, Energy and Treasury, as well as senior officials from the White House.

Vice Commerce Minister Wang Shouwen heads the vice ministerial level talks for China, though Vice Premier Liu He, a top economic adviser to Xi, made an appearance at a meeting on Monday.

China is keen to put an end to its trade dispute with the United States but will not make any "unreasonable concessions" and any agreement must involve compromise on both sides, state newspaper the China Daily said on Wednesday.

The paper said in an editorial that Beijing's stance remains firm that the dispute harms both countries and disrupts the international trade order and supply chains.

In what is widely seen as a goodwill gesture, China on Tuesday issued long-awaited approvals for the import of five genetically modified crops, which could boost its purchases of U.S. grains as farmers decide which crops to plant in the spring.

On Monday, Chinese importers made another large purchase of U.S. soybeans, their third in the past month.

—CNBC contributed to this report.