Trump raised eyebrows at a Washington media dinner on Saturday when he said "they, by the way, called up a couple of days ago and said 'we would like to talk.'

"And I said, 'so would we, but you have to de-nuke, you have to de-nuke,'" Trump added.

A senior administration official, speaking on condition of anonymity, told AFP that Trump had in fact been referencing a call he had on Thursday with South Korean President Moon Jae-in.

Pyongyang is the Korean peninsula's only nuclear-armed power, prompting speculation of rare direct contact between US and North Korean officials.

Moon has prodded Trump toward negotiations, and has met North Korean officials himself.

Trump has taken a more bellicose position, suggesting military action is possible if North Korea does not stop efforts to develop a nuclear armed missile capable of hitting the continental United States.