Speaking at a rally in Elkhart, Indiana, the US president said his relationship with the secretive communist state's leader Kim Jong-un was "good", adding that he would meet him "to secure a future of peace and prosperity for the world".
He told his cheering supporters: "Something very good is going to happen".
Mr Trump was joined at the rally by Vice President Mike Pence, Indiana's former governor and a number of senior members of their Republican Party in the state.
Ahead of Mr Trump's speech, Mr Pence said the president "embraces his role as a leader of the free world" and part of that was his work on brokering a deal with North Korea to stop developing its nuclear weapons programme.
A historic summit between Mr Trump and Mr Kim is set to take place in Singapore on 12 June.
Mr Pence also praised the president for helping to secure the recent release of three American citizens - Kim Dong Chul, Kim Hak-song, and Kim Sang Duk - that had been held by North Korea.
In his own speech, Mr Trump lashed out at the media, labelling unamed reports that his actions would "get us into a nuclear war" as "fake news".
He added: "You know what gets you into nuclear wars, and you know what gets you into other wars, weakness".
Lamenting his predecessor, he said Barack Obama "paid $1.8bn for hostages", while the men recently freed from North Korea, "came home for nothing".
It is thought Mr Trump may have been referring to the Iran nuclear deal, which saw the US pay $1.7bn to Tehran, $400m of which was to settle a decades-old legal matter involving sales of military equipment just ahead of the 1979 Iranian revolution.
Iran which subsequently announced it would release four American hostages. The second and third payments - totalling $1.3bn - were made later and the Obama administration later admitted it withheld some of the money, part of it interest on Iranian money held in the US since the 1970s, as an inducement for actually releasing the Americans.
Mr Trump continued by saying that his North Korean counterpart "did a great service to himself and his country," although this was greeted with a mixed reaction from the crowd, which appeared uncertain whether to cheer for the leader who just last year threatened to launch intercontinental ballistic missiles at US territory Guam, Hawaii, and even the west coast of the US.
The president said the hostages "came out with respect," adding that “what [Mr Kim] did was the right thing, but they came out for nothing and the others came out for $1.8bn in cash".
Hopes for the summit remain high in the diplomatic world as it comes just a little over a month after a historic meeting between Mr Kim and South Korean President Moon Jae-in.
The pair had met in the neutral border territory Demilitarised Zone to sign the Panmunjom Declaration for Peace, Prosperity and Unification of the Korean Peninsula during the Inter-Korean Summit and officially ended the war that began when the north and south split in a battle over communism and democracy that began on 25 June 1950.