“Kim Jong-un said that we will believe in President Trump’s positive way of thinking, wait with patience and in good faith and, together with the US, advance step by step toward the goal to be reached by the two countries,” KCNA said.

It said Kim expressed “large satisfaction” at receiving a “great” letter from Trump and a briefing about the results of the negotiations from the North Korean delegation that visited Washington last week but did not elaborate.

Kim ordered working-level preparations for the second North Korea-US summit to be done well, KCNA said.

The White House said last week a second Trump-Kim summit would be held in late February but did not say where.

That follows their landmark first summit in Singapore last June, which produced a promise to work towards the complete denuclearisation of the Korean peninsula. Progress since then has been patchy.

Kim has indicated to South Korean President Moon Jae-in he would undertake a “groundbreaking” denuclearisation measure, South Korean newspaper DongA Ilbo reported on Thursday.

The newspaper, citing an unidentified source with direct knowledge of the US-North Korea situation, said the same had been made clear to Trump during senior North Korean official Kim Yong-chol’s Washington visit last week.

Trump to hold second summit with Kim Jong-un at end of February, White House says

North Korea has hinted, for example, at the possibility of agreeing to the US demand for verification of denuclearisation efforts before it discards its Yongbyon nuclear facilities.

In turn, the United States has mentioned potential measures such as easing limits on oil imports, a conditional restart of the Kaesong industrial zone in North Korea, and opening a liaison office in Pyongyang, DongA reported.

DongA also said that, according to several South Korean government sources, talks between officials from North Korea, the United States and South Korea near Stockholm this week appeared to have been constructive in setting some of the agenda for the second Trump-Kim summit.

The US State Department did not respond to a request for comment on the DongA report.

The White House said after Trump met Kim Yong-chol, the North’s chief nuclear negotiator, last week that economic sanctions against Pyongyang would be maintained despite agreeing to the second summit.

Kim Yong-hyun, a professor in North Korea studies at Dongguk University, told the Post the report indicated the two countries have “reached an accord on a broad road map for resolving the North's nuclear issue”.

“At the summit, the North is likely to offer to freeze or dismantle its Yongbyon nuclear site and accept outside experts for verification, while the US side will probably announce a plan to open a liaison office in Pyongyang and express its will to ease sanctions proactively,” he said.

But Choi Kang, vice-president of the Asan institute, said he was “sceptical” that any substantial progress had been made on negotiations to date. “Kim and Trump are both playing it up in order to create a favourable atmosphere for their second summit, but the question is how much the North is willing to yield in denuclearisation as Trump needs substantial results to avoid criticism that he is only doing a reality show with the North's nuclear issue.”

Trump has said there is “no rush” and “no time limit” on denuclearisation negotiations, but Secretary of State Mike Pompeo has given varying statements about the degree of Washington’s patience.

Pompeo said after the Singapore summit the United States hoped to achieve “major disarmament” by North Korea by the end of Trump’s current term in office in January 2021. He has subsequently said he would not put a timeline on talks.

He told Fox News in an interview broadcast on Wednesday there had been progress in stopping North Korea’s nuclear and missile-testing programmes.

“Chairman Kim continues to assure the president of the United States he is intent on denuclearisation and I hope that at the end of February, when the two leaders get together, we can make a substantial step along the way,” Pompeo said.

He said on Tuesday he saw an important role for the private sector in helping to develop North Korea if progress was made.

Additional reporting by Park Chan-kyong