The shocking statement led to the president's announcement that he will meet North Korean leader Kim Jong Un on February 27 and 28 in a summit in Vietnam.
"As part of a bold new diplomacy, we continue our historic push for peace on the Korean Peninsula", the president said on the House floor.
Senate Democratic Leader Chuck Schumer is dismissing as "a real eye-roller" President Donald Trump's assertion that if anyone else had been elected president the US would be at war with North Korea.
The choice of Vietnam as a meeting place for the second summit could highlight a path forward for North Korea, The Washington Post said.
The first Trump-Kim summit was held in Singapore in June 2018, but negotiations failed to make much headway owing to disagreements on the concept of denuclearization.
Phuc last month told Bloomberg News that, if selected as the Trump-Kim summit host, his country would "do our best to facilitate the meeting".
As US-North Korea talks were revived in January following slow progress since their Singapore summit, concessions from the two sides that will bring denuclearization negotiations to the next level have been drawing keen attention from the worldwide community.
He said his relationship with Kim "is a good one".
"North Korea has said normalization must start before denuclearization, while the USA maintains that the North must hand over its nuclear weapons before any normalization can begin", NPR reported in November.
But a declaration to end the war would have to be signed by the leaders of the main protagonists, both Koreas, China and the United States, and experts say time is very short to coordinate such a step by the end of this month.
Trump voiced guarded hope that intensifying negotiations with Afghanistan's Taliban would bring for a "possible political solution" to end the longest-ever United States war. "He ratcheted up the rhetoric about "Little Rocket Man" at the start of his administration, threatening "fire and fury" should North Korea attack the U.S".
"It bears repeating that Trump just claimed on national TV that had Clinton been elected North Korea would have nuked us", another user noted.
The three-year Korean War ended with an armistice that left the two Koreas technically still at war.
US President Donald Trump makes a comment during his State of the Union address to a joint session of Congress in the House Chamber of the US Capitol in Washington, DC on February 5. North Korea has an embassy in Hanoi and reports suggest that Kim Jong Un is interested in following Vietnam's economic and political example.