Washington: Fresh from a dramatic trip to North Korea and ahead of a historic summit, US Secretary of State Mike Pompeo says the United States will provide economic help if the country gives up its nuclear weapons, and perhaps ultimately agree to normalised relations.

Pompeo, two weeks and one day on the job, returned to the US on Thursday from what he called a "productive" meeting with North Korea's Kim Jong-un to agree on details for the Trump-Kim summit. He brought home three American prisoners freed by Kim in what Pompeo said was an important gesture that helped pave the way for the meeting.

Contrasting the wealth of South Korea to the poverty and deprivation of the North, Pompeo said the Trump administration was willing to provide assistance to North Korea if Kim met US demands to forfeit its nuclear weapons. Kim has said that North Korea now has the capability to strike the continental United States.

"If Chairman Kim chooses the right path, there is a future brimming with peace and prosperity" for his people, Pompeo said at the US State Department, following a meeting with the foreign minister of South Korea on Friday, US time.

"If North Korea takes bold action to quickly denuclearise, the United States is prepared to work with North Korea to achieve prosperity on par with our South Korean friends," Pompeo added.