Pyongyang/Washington: North Korea has said it may pull out of a summit with US President Donald Trump if the US insists it gives up its nuclear weapons.
The highly anticipated meeting between Trump and North Korea's Kim Jong-un is due to take place on June 12.
The White House has responded by saying it is still hopeful the meeting will go ahead. "The president is ready if the meeting takes place. If it doesn't, we'll continue the maximum pressure campaign that's been ongoing," said spokesperson Sarah Sanders.
The groundbreaking agreement for Kim and Trump to meet came about as North Korea said it was committed to denuclearising the Korean peninsula.
Exactly what that would entail has remained unclear, but North Korea has invited foreign media to witness the dismantling of its main nuclear test site later this month.
Bolton recently said North Korea could follow a "Libya model" of verifiable denuclearisation, but this alarms Pyongyang, which watched Libya's Colonel Gaddafi give up his nuclear programme only for him to be killed by Western-backed rebels a few years later.
Kim's statement, carried by state media, said that if the US "corners us and unilaterally demands we give up nuclear weapons we will no longer have an interest in talks" and "will have to reconsider" attending the 12 June summit in Singapore.
He said North Korea did have "high hopes" but that it was "very unfortunate that the US is provoking us ahead of the summit by spitting out ludicrous statements".
Kim Kye-gwan is known to be highly respected in the North Korean leadership and has taken part in negotiations with the US before. There is very little chance his comments were not personally endorsed by Kim Jong-un.
Hours before the announcement, in a sign of growing problems, North Korea had also pulled out of a meeting scheduled with South Korea on Wednesday. because of anger over the start of US-South Korea joint military drills.
North Korea had earlier said it would allow them to go ahead, but then called them "a provocative military ruckus" which was undermining its diplomatic efforts.