US president Donald Trump said America has not been notified about North Korea’s threat to cancel his planned summit with Kim Jong Un next month.
Mr Trump said he will still insist on the country’s denuclearisation.
North Korea threatened to scrap the historic summit next month between the two leaders, saying it has no interest in a “one-sided” affair meant to pressure the North to abandon its nuclear weapons.
Mr Trump said the White House has not been notified at all about the threat.
He added: “We haven’t seen anything. We haven’t heard anything. We will see what happens.”
The warning from North Korea’s first vice foreign minister came after the country abruptly cancelled a high-level meeting with South Korea to protest against US-South Korean military exercises that the North has long claimed are an invasion rehearsal.
Behind the scenes, White House aides tried to soothe South Korean frustrations over the cancelled meeting with the North as they continue to plan for the summit, planned for June 12 in Singapore, as if nothing had changed.
US officials compared the threat to Mr Trump’s own warning that he might walk away from the summit if he determines Mr Kim is not serious about abandoning his nuclear programme, saying it did not appear to be serious.
The direction from the Oval Office to White House aides and other US national security agencies Wednesday was to downplay the North Korean threats and not “take the bait” by overreacting to the provocation, said a senior US official.
National Security Adviser John Bolton told Fox News Radio on Wednesday: “We are trying to be both optimistic and realistic at the same time.”
Mr Bolton, who was criticised by the North for saying that the US is seeking to seek an outcome similar to Libya’s unilateral nuclear disarmament, said the personal attack raised the question of “whether this really is a sign that that they’re not taking our objective of denuclearisation seriously”.
North Korean first vice foreign minister Kim Kye Gwan said in a statement carried by state media that “we are no longer interested in a negotiation that will be all about driving us into a corner and making a one-sided demand for us to give up our nukes and this would force us to reconsider whether we would accept the North Korea-US summit meeting”.
Mr Trump surprised even aides in March when he accepted an invitation from Mr Kim to meet.
Secretary of State Mike Pompeo has met with the North Korean leader twice to lay the groundwork for the summit, and reported that Mr Kim had agreed to place his nuclear arsenal on the negotiating table.