President Donald Trump said on Friday he has directed Secretary of State Mike Pompeo to delay a planned trip to North Korea, citing insufficient progress on denuclearisation.
Trump put some blame on Beijing, saying he does not believe China is helping "because of our much tougher Trading stance".
The surprise announcement appeared to mark a concession by the president to domestic and international concerns that his prior claims of world-altering progress on the peninsula had been strikingly premature.
"I have asked Secretary of State Mike Pompeo not to go to North Korea, at this time, because I feel we are not making sufficient progress with respect to the denuclearisation of the Korean Peninsula," Trump tweeted on Friday, barely two months after his June meeting with the North's Kim Jong Un in Singapore.
Trump's comment followed a report issued on Monday by the International Atomic Energy Agency outlining "grave concern" about the North's nuclear programme.
It came a day after Pompeo appointed Stephen Biegun, a senior executive with the Ford Motor Co, to be his special envoy for North Korea and said he and Biegun would visit next week.
The State Department never confirmed details of the trip, but it had been expected that Pompeo would be in Pyongyang for at least several hours on Monday, according to several diplomatic sources familiar with the plan.