Trump received Kim Jong Un letter seeking second meet: White House

North Korea's leader Kim Jong Un and US President Donald Trump, pictured at the start of their historic US-North Korea summit, are preparing for a second meeting. (Photo: AFP/Saul Loeb)

"It was a very warm, very positive letter," White House spokeswoman Sarah Sanders said, adding that the message showed Pyongyang's "continued commitment to focus on denuclearisation" on the Korean Peninsula.

"The primary purpose of the letter was to schedule another meeting with the president, which we are open to and are already in the process of coordinating," she said at the first White House press briefing in nearly three weeks.

Sanders added that the letter was "further evidence of progress" in Washington's relationship with Pyongyang.

Trump and Kim held a historic summit in Singapore in June that raised prospects of a breakthrough on curtailing North Korea's nuclear program.

Despite follow-on negotiations on denuclearising the peninsula hitting a snag leading to Secretary of State Mike Pompeo cancelling a planned trip to the North late last month, the new letter showed signs that the discussions remain alive after weeks of apparent deadlock.

"We think it's important and we're glad that we're making progress," Sanders said, adding that Trump deserves the "credit" for bringing the two parties to the table.

"At the end of the day, ultimately, it's always going to be best when you can have the two leaders sit down," she added.

The White House has pointed to a series of accomplishments in recent months, including a release of US hostages, the repatriation of war remains believed to be of US service members and a pause in North Korea's missile and nuclear tests, to suggest progress between the foes.

And on Sunday, North Korea refrained from displaying its intercontinental missiles - long a bone of contention in its nuclear tensions with Washington - in a massive parade through Pyongyang celebrating the country's 70th birthday.

"STILL WAITING"

The latest parade "for once was not about their nuclear arsenal," Sanders said.

Trump thanked Kim for the gesture, saying on Twitter: "This is a big and very positive statement from North Korea."

Sanders was asked whether the next Trump-Kim meeting would take place in Washington, but she demurred, saying, "we'll let you know when we have further details."

The letter's arrival was confirmed as Trump's top security adviser said the White House was looking to North Korea for next steps.

"We're still waiting for them. The possibility of another meeting between the two presidents obviously exists," said National Security Advisor John Bolton.

"But President Trump can't make the North Koreans walk through the door he's holding open. They are the ones that have to take the steps to denuclearize. And that's what we are waiting for."

Bolton said in a speech to the Federalist Society that during the Singapore meeting with Trump in June, Kim committed to getting rid of his nuclear weapons, and later agreed with South Korean President Moon Jae-in that it could be done in one year.

After his speech, Bolton told reporters "it's entirely possible" for the two leaders to meet by year's end.

WINDOW OF OPPORTUNITY

The nuclear envoys of South Korea and the United States also held a meeting on Tuesday as part of efforts to jumpstart stalled nuclear talks between Pyongyang and Washington.

Lee Do-hoon, South Korea's nuclear negotiator, told reporters that he and his US counterpart Stephen Biegun discussed how to bring progress on the North's denuclearisation and establishing peace on the Korean peninsula.

"We take this very seriously, the responsibility that is on both of us," Biegun told Lee at the start of the talks.

"But we also have a tremendous opportunity created by President Trump, by President Moon and by Chairman Kim. We need to do everything we can to make the most of this moment of opportunity."

Harry Kazianis, director of defence studies from the Centre for the National Interest, a think tank in Washington reckoned Trump was right to pursue a second meeting with the North Korean leader.

"When you combine Kim's pledge to denuclearise by the end of Trump's first term, as well as not displaying any long-range ballistic missiles during the North's recent 70th anniversary celebrations, there are reasons for optimism," he said.