JULIE Bishop says Donald Trump will deserve the highest praise if he can help broker peace with North Korea but she remains sceptical of the rogue nation's promise to denuclearise.

"There's something that I like about it because you are there, you are actually there", Trump said at a news conference in the White House Rose Garden.

"If we meet often and build trust with the United States and if an end to the war and nonaggression are promised, why would we live in difficulty with nuclear weapons?"

Trump is preparing for his own summit with Kim, which he said would take place in the next three to four weeks.

"The US leader has been eager to play up his role in achieving a breakthrough with Pyongyang through his "maximum pressure" campaign involving tough rhetoric, stronger sanctions and diplomatic efforts to further isolate the regime".

The presidential Blue House, or Cheong Wa Dae, had set water, tea and an ashtray on the table near the benches where the two leaders sat together, but Mr Kim, who is thought to be aged 34, did not take out a cigarette in front of Mr Moon, 65.

He has previously said the US President deserved "big credit" for the recent thawing in relations with North Korea, The Independent reports.

Trump's new national security adviser John Bolton, who is known for his hardline approach on North Korea, is pushing for the country's nuclear weapons programme to be eliminated and has rejected any incremental approach, saying it was tried by previous administrations and had not worked.

The widow said Moon, who met with current North Korean leader Kim Jong Un last week, should also receive the prize. "We are expecting the North's implementation".

Crowds in Michigan chanted "Nobel, Nobel" as President Donald Trump spoke about North Korea.

President Moon is also pushing for multi-lateral talks sometime in June with the two Koreas, the U.S., and possibly China - to ensure the success of the North Korea-U.S. summit.

The conservative Chosun daily said in an editorial that the agreement was positive in terms of repairing frozen ties between the two Koreas but left much to be desired in terms of denuclearisation. And for a complete peace to arrive South and North Korea will collaborate closely.

It seems Kim Jong Un is not the bloodthirsty and warmongering dictator as some people and countries portrayed him, at least for a moment.

Consequently, this also drove the South Koreans crazy and a lot of them found Kim's reaction to be cute and charming. Ministry spokeswoman Choi Hyunsoo said Seoul expected North Korea to do the same.