In this file photo taken on Feb. 27, 2019, U.S. President Donald Trump shakes hands with North Korea's leader Kim Jong-un following a meeting at the Sofitel Legend Metropole hotel in Hanoi. AFP

U.S. President Donald Trump could meet again with North Korean leader Kim Jong-un if he believes a summit would help his reelection chances, Trump's former National Security Adviser John Bolton said Thursday.

Bolton's comment comes after President Moon Jae-in renewed his resolve to enable a fourth Trump-Kim meeting before the U.S. presidential election in November.

While Trump and Kim last met in the Demilitarized Zone on the inter-Korean border in June 2019, efforts to reach a nuclear deal have stalled due to differences over the scope of North Korea's denuclearization and sanctions relief from the U.S.

"I think President Trump ― everybody can read the public opinion polls. He's way behind," Bolton said during a press conference with foreign reporters in New York.

"That doesn't mean the election is over by any stretch of the imagination, but you know we have a phrase in the United States called the 'October surprise' just before an election," he said. "If the president felt he was in deep, deep trouble, another meeting with his friend Kim Jong-un might look like something that could turn things upside down again."