Two US officials — Secretary of State Mike Pompeo and Mick Mulvaney, the White House's acting chief of staff — joined the dinner session, which last about an hour and a half. Kim Yong-chol, a senior official of the Workers' Party of Korea, and DPRK Foreign Minister Ri Yong-ho were at the dining table as well.

The dinner session was thought to serve as a tone-setting test for the formal talks scheduled on Thursday morning, which may decide the future of a peace process that has been stalled after the two leaders' Singapore summit in June.

On Wednesday, Chinese State Councilor and Foreign Minister Wang Yi said that Beijing hopes the Hanoi summit between Kim and Trump will take an important step forward to achieve denuclearization and establish a peace mechanism on the Korean Peninsula.

"China expects the meeting between leaders of the DPRK and the US will continue moving forward in the direction of the 'dual-track' approach," Wang said at a news conference after the 16th meeting of the foreign ministers of China, Russia and India in Wuzhen, Zhejiang province.

Analysts have described Kim and Trump's Singapore summit as focused on breaking the ice to pave the way for full-scale diplomacy on denuclearization, improved ties and a formal conclusion to the war on the Korean Peninsula, going beyond the armistice reached in 1953. Now the two nations are facing a more daunting task of attempting to reach specific deals over details, going beyond a vaguely worded joint statement, they said.