The US has said it could help rebuild North Korea if it agrees to give up nuclear weapons.
Secretary of State Mike Pompeo said on Friday that America would be "prepared to work with North Korea to achieve prosperity on the par with our South Korean friends."
South Korea is one of the world's top 20 economies, after turning towards capitalism at the end of the Korean war in 1953.
His comments come just weeks ahead of Trump's meeting with Kim Jong-un in Singapore.
The Secretary of State returned from a visit to North Korea on Thursday morning in which he secured the release of three detained Americans.
He said that he had "good" discussions with Kim Jong-un during his visit.
Mr Pompeo added that the denuclearisation would have to be "complete" and "verifiable".
President Trump is set to meet the North Korean leader on June 12 in Singapore where they are likely to discuss the issue again.
During the landmark summit with South Korea in April, Kim Jong-un pledged to work towards eradicating nuclear weapons.
He had already said the north would suspend its nuclear and long-range missile tests ahead of the talks.
During the summit, Mr Kim said: "We are at a starting line today, where a new history of peace, prosperity and inter-Korean relations is being written."
