“It’ll be after the midterms,” Trump told reporters as he flew to Iowa for a political rally on Tuesday. “I just can’t leave now.”
The midterm elections take place on November 6.
The US president said earlier “incredible” progress had been made in bilateral talks with the isolated North Asian country.
Trump and Kim held their first summit in June in Singapore where they discussed ending the reclusive state’s nuclear weapons programme and formally ending decades of hostilities between the two countries.
Trump was upbeat on de-nuclearisation progress so far, as well as his relationship with Kim, whom he once called “Little Rocket Man“.
“You got no rockets flying, you have no missiles flying, you have no nuclear testing,” Trump said in the Oval Office. “We’ve made incredible progress – beyond incredible.
“We have a very good relationship with Chairman Kim. I like him, he likes me – the relationship is good.”
US Secretary of State Mike Pompeo who met Kim on Monday in Pyongyang – his fourth visit this year – said the two sides were now “pretty close” to agreeing on the details for a second summit.
“While there is still a long way to go and much work to do, we can now see a path to where we’ll achieve the ultimate goal, which is the full and final verified denuclearisation of North Korea,” Pompeo told reporters.
Pompeo said Kim indicated he was ready to allow international inspectors into North Korea’s Punggye-ri nuclear testing site and the Sohae missile engine test facility as soon as there was agreement on logistics.
Trump welcomed the recent return of remains of US soldiers killed during the Korean War, but said sanctions could not be lifted without further action from North Korea.
“I’d love to remove them, but we have to get something for doing it,” Trump said.
Kim has yet to comply with US demands for a complete inventory of its weapons and facilities, or to take irreversible steps to give up its nuclear arsenal. Experts said the North Korean leader appeared to be only repackaging and dragging out past pledges.
The World Food Programme said on Tuesday the supply of food remained precarious in North Korea, where one in five children is stunted by malnutrition.
More than 10 million North Koreans, nearly 40 percent of the population, are undernourished and need humanitarian aid, it said.