North Korea is threatening to cancel the forthcoming summit with the US due to ongoing military exercises between America and South Korea, according to reports.
A meeting between the two Koreas at a border village to discuss setting up military and Red Cross talks to reduce border tension and restart reunions between families separated by the Korean War has also been cancelled by Pyongyang, Yonhap News Agency said.
North Korea's Korean Central News Agency reported that Pyongyang was also questioning whether next month's summit between North Korea's Kim Jong Un and US president Donald Trump can also take place as planned.
However, the US has said it is going ahead with plans for the meeting between the two leaders.
Yonhap said the two-week military exercise between the US and South Korea started on Friday.
The operations are thought to have involved 100 warplanes.
The Korean Central News Agency reported: "The United States will also have to undertake careful deliberations about the fate of the planned North Korea-US summit in light of this provocative military ruckus jointly conducted with the South Korean authorities."
On Tuesday, South Korea's military said North Korea was moving ahead with plans to close its nuclear test site next week, an assessment backed by US researchers who say satellite images show the North has begun dismantling facilities at the site.
The site's closure was set to come before Mr Kim and Mr Trump's summit, which had been shaping up to be a crucial moment in the global diplomatic push to resolve the nuclear stand-off with the North.
The US state department said Washington has not heard anything directly from Pyongyang or Seoul which would change plans for the historic meeting, proposed for June 12.
Spokeswoman Heather Nauert said Mr Kim had previously indicated he understood the need and purpose of the US continuing its long-planned joint exercises with South Korea.