A meeting between US president Donald Trump and North Korean leader Kim Jong Un would mark a dramatic breakthrough in efforts to resolve the tense standoff over North Korea's effort to develop a nuclear-tipped missile capable of hitting the US mainland. (Photo: AFP)

Washington: President Donald Trump on Thursday expressed a willingness to meet North Korean leader Kim Jong Un by May in response to Kim's invitation to hold the first meeting between leaders of the United States and North Korea, a South Korean envoy said.

Kim has committed to "denuclearisation" and to suspending nuclear or missile tests, South Korea's National Security Office head Chung Eui-yong told reporters at the White House after briefing Trump on South Korean officials' meeting with Kim on Monday.

A meeting between Kim and Trump, who have exchanged bellicose insults in the past year that have raised fear of war, would mark a dramatic breakthrough in efforts to resolve the tense standoff over North Korea's effort to develop a nuclear-tipped missile capable of hitting the US mainland.

"I told him (Trump) in our meeting that North Korean leader Kim Jong Un said that he's committed to denuclearisation," Chung said. "Kim pledged that North Korea will refrain from any further nuclear or missile tests."

"He expressed his eagerness to meet President Trump as soon as possible," he said. "President Trump appreciated the briefing and said he would meet Kim Jong Un by May to achieve denuclearisation."

There was no immediate comment from the White House on the South Korean envoy's comments.

Trump's aides have been wary of North Korea's diplomatic overtures because of its history of reneging on international commitments.

Chung and National Intelligence Service chief Suh-hoon flew to Washington earlier on Thursday to explain North Korea's stance on possible future talks with Washington and the prospect of Pyongyang suspending nuclear tests if the security of the North's government is assured.

Earlier Thursday, US Secretary of State Rex Tillerson said that though "talks about talks" might be possible with Pyongyang, denuclearisation negotiations were likely a long way off.