A US delegation has met North Korean officials in the Demilitarized Zone as planning moved ahead for a possible summit between President Donald Trump and North Korean leader Kim Jong Un.

South Korea’s president Moon Jae-in gave details about his surprise meeting on Saturday with Mr Kim in the Panmunjom truce village, saying Mr Kim had committed to sitting down with Mr Trump and to a “complete denuclearisation of the Korean Peninsula”.

Secretary of State Mike Pompeo has asked veteran American diplomat Sung Kim to handle pre-summit negotiations.

A White House logistical group was also sent to Singapore on Sunday to prepare in case the summit takes place. It was led by Joe Hagin, White House deputy chief of staff for operations.

“Our United States team has arrived in North Korea to make arrangements for the Summit between Kim Jong Un and myself,” Mr Trump tweeted. “I truly believe North Korea has brilliant potential and will be a great economic and financial Nation one day. Kim Jong Un agrees with me on this. It will happen!”

Sung Kim, the US ambassador to the Philippines, also served as ambassador to South Korea and was part of the US negotiating team that last held substantive denuclearisation talks with North Korea during the George W Bush administration in 2005.

The developments, after last week’s whirlwind of uncertainty, appeared to flesh out Mr Trump’s assertion that the June 12 summit in Singapore that he cancelled on Thursday could take place as first scheduled.

Mr Trump told reporters on Saturday that there was “a lot of goodwill,” that the original plan was still being considered and that “that hasn’t changed”.

“We continue to prepare for a meeting,” State Department spokeswoman Heather Nauert said in Washington as she confirmed that an American delegation was “in ongoing talks with North Korean officials” in Panmunjom in the DMZ, which separates the two Koreas.

The Korean leaders’ second summit in a month saw bear hugs and broad smiles, but their quickly arranged meeting appears to highlight a sense of urgency on both sides of the world’s most heavily armed border.

The Koreas’ talks, which Mr Moon said Mr Kim requested, capped a whirlwind 24 hours of diplomatic back-and-forth.

North Korea Koreas Tensions
South Korean president Moon Jae-in writes in a visitor’s book as North Korean leader Kim Jong Un looks on (AP)

It allowed Mr Moon to push for a US-North Korean summit that he sees as the best way to ease animosity that had some fearing a war last year.

Mr Kim may see the sit-down with Mr Trump as necessary to easing pressure from crushing sanctions and to winning security assurances in a region surrounded by enemies.

Mr Moon told reporters on Sunday that Mr Kim “again made clear his commitment to a complete denuclearisation of the Korean Peninsula,” and told the South Korean leader that he is willing to cooperate to end confrontation and work toward peace for the sake of the successful North Korea-US summit.

Mr Moon said he told Mr Kim that Mr Trump has a “firm resolve” to end hostile relations with North Korea and initiate economic cooperation if Kim implements “complete denuclearisation”.

“What Kim is unclear about is that he has concerns about whether his country can surely trust the United States over its promise to end hostile relations (with North Korea) and provide a security guarantee if they do denuclearisation,” Mr Moon said.

“During the South Korea-US summit, President Trump said the US is willing to clearly put an end to hostile relations (between the US and North Korea) and help (the North) achieve economic prosperity if North Korea conducts denuclearisation.”

Mr Moon said North Korea and the United States will soon start working-level talks to prepare for the Kim-Trump summit. He said he expects the talks to go smoothly because Pyongyang and Washington both know what they want from each other.

Mr Kim, in a telling line from a dispatch issued by the North’s state-run news service earlier on Sunday, “expressed his fixed will on the historic (North Korea)-US summit talks.”

During Saturday’s inter-Korean summit, the Korean leaders agreed to “positively cooperate with each other as ever to improve (North Korea)-US relations and establish (a) mechanism for permanent and durable peace.”

They agreed to have their top officials meet again on June 1.

Mr Moon said military generals and Red Cross officials from the Koreas will also meet separately to discuss how to ease military tensions and resume reunions of families separated by the 1950-53 Korean War.