Former National Security Adviser John Bolton claims that President Donald Trump may have another meeting with North Korean leader Kim Jong Un prior to this fall’s election as an “October Surprise.” 

“We have a phrase in the United States called the 'October surprise' just before an election,” Bolton told reporters Thursday during a video seminar held by the Foreign Press Association in New York. "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."

South Korean leader Moon Jae-in has also reportedly proposed another summit between Trump and Kim, as tensions rise on the Korean Peninsula. North Korea has shot down the idea of another summit, as sanctions continue to debilitate its economy. 

"Is it possible to hold dialogue or have any dealings with the U.S, which persists in the hostile policy towards [North Korea] in disregard of the agreements already made at the past summit?" North Korean First Vice-Foreign Minister Choe Son Hui said Thursday in a statement. "We do not feel any need to sit face-to-face with the U.S., as it does not consider the [North Korea-U.S.] dialogue as nothing more than a tool for grappling its political crisis."

The U.S. and North Korea last met for nuclear negotiations in Sweden in October, but talks fell through on the first day of diplomatic discussions. Washington wants Pyongyang to pursue a path to denuclearization, while North Korea wants the U.S. to lift economic sanctions. Kim previously met Trump for summits in Vietnam in February 2019 and in Singapore in June 2018, but no concrete nuclear agreement was reached. 

Bolton, who served as National Security Adviser from April 2018 to September 2019, claimed in his memoir that U.S. officials didn't want Trump alone in the room with Kim at the Hanoi meeting. Sources told TIME in April 2019 that Bolton a month earlier had "told other senior officials that the U.S. would impose sanctions on two Chinese shipping companies for violating international sanctions on North Korea" but the next day Trump abruptly canceled the sanctions.

North Korea has expressed frustrations with the sanctions, with Kim promising to unveil a “new strategic weapon” this year. The North Korean military also recently destroyed an inter-Korean liaison office, due to anger over anti-regime leaflets coming in from the South. 

A nuclear deal with North Korea has been a major foreign policy goal of the Trump administration. Bolton has said that North Korea would never give up its nuclear arsenal, while Democratic presidential candidate Joe Biden has lambasted Trump’s meetings with Kim. 

North Korea has been reportedly expanding its nuclear arsenal amid the stalled negotiations. According to a June report from the Stockholm Peace Research Institute, Pyongyang has added up to 20 new nuclear warheads since January 2019, with the country reportedly having between 30 to 40 warheads in total.