A historic meeting between Mr Trump and North Korea’s Kim Jong Un over denuclearisation could be announced by week’s end.
Indiana Republican Luke Messer unveiled a letter today to members of the Norwegian Nobel Committee that was signed by 18 Republicans.
The letter says North Korea has evaded demands from the international community to end its aggressions, but that Mr Trump’s “peace through strength policies are working” and bringing North Korea to the negotiating table.
Mr Messer is running for the US Senate in Indiana, where support for Mr Trump has become a litmus test for Republican voters.
Several other Republicans on the letter are also running for governor or senator.
The two Koreas agreed to rid their peninsula of nuclear weapons in historic talks between the two leaders last week.
A joint statement issued by Kim Jong Un and Moon Jae-in after Friday’s summit said the two had confirmed their goal of achieving “a nuclear-free Korean peninsula through complete denuclearisation”.
The statement did not provide any new specific measures how to achieve the objective.
North Korea has placed its nuclear weapons up for negotiations.
It has previously used the term “denuclearisation” to say it can disarm only when the US withdraws its 28,500 troops in South Korea.
The two countries also said they will jointly push for talks with the US, and potentially China, to officially end the 1950-53 Korean War, which stopped with an armistice and left the Koreas still technically at war.
North Korean leader Mr Kim and South Korean President Moon announced after their summit that the Koreas will push for three-way talks including Washington or four-way talks that also include Beijing on converting the armistice into a peace treaty and establishing permanent peace on the Korean peninsula.