US President Donald Trump and North Korean leader Kim Jong Un failed to reach an agreement on denuclearisation of the Korean peninsula at their summit in Hanoi, Vietnam on Thursday, the White House said.
Earlier, both Trump and Kim had expressed hope for progress on improving relations and on the key issue of denuclearisation, in their talks in the Vietnamese capital, Hanoi.
"The two leaders discussed various ways to advance denuclearization and economic driven concepts," White House spokeswoman Sarah Sanders said.
"No agreement was reached at this time, but their respective teams look forward to meeting in the future," Sanders added.
Trump had been scheduled to hold a "joint agreement signing ceremony" with Kim at the conclusion of their summit talks, according to an earlier White House announcement.
Both leaders left the venue of their talks, the French-colonial-era Metropole hotel, at 1.25 pm on Thursday, without attending a planned lunch together, and returned to their hotels.
Donald Trump is now due to hold a news conference at 2 pm.
News of the change in a schedule sent South Korea's currency lower and knocked regional stock markets.
Earlier Kim Jong Un and Donald Trump, seated across from each other at a conference table, appeared confident of progress.
"If I'm not willing to do that, I won't be here right now," Kim told reporters through an interpreter when asked if he was ready to give up his nuclear weapons.
Trump, responding to that, said, "That might be the best answer you've ever heard."
Kim did not elaborate on what "denuclearisation" would entail, but when asked if he was ready to take concrete steps, he said that they had just been talking about that.
While the United States is demanding North Korea give up all of its nuclear and missile programmes, the North wants to see the removal of a US nuclear umbrella for its Asian allies such as South Korea and Japan.
The two leaders' summit in Singapore in June, the first between a sitting US president and a North Korean leader, produced a vague statement in which Kim pledged to work toward denuclearisation of the Korean peninsula.
But there has been little progress since.