U.S. Sen. Lindsey Graham said in an interview Sunday that President Donald Trump would seek to resolve the North Korean nuclear crisis in his first term, adding that if Pyongyang backs out of a landmark summit scheduled for next month, the two countries would be “on the path to conflict.”

Speaking on “Fox News Sunday,” the Republican senator said that Trump was determined to see a through a deal in which the North Korean regime of Kim Jong Un relinquishes its nuclear weapons program. Trump is due to meet Kim in Singapore on June 12 in a summit that would see the leaders of the two countries hold talks for the first time.

But in the first major sign of trouble amid warming ties, the North on Wednesday abruptly threatened to cancel the hotly anticipated summit if Washington presses ahead with its demand that Pyongyang unilaterally relinquish its nuclear arsenal and continued to speak of a “Libya-style” denuclearization process.

North Korea has routinely pointed to U.S. military interventions as justification for its nuclear arsenal, citing the fate of late Libyan leader Moammar Gadhafi, who gave up his fledgling nuclear weapons program. It also has a long history of reneging on deals with the U.S. and the international community to give up its nuclear arms.

Asked if Pyongyang was up to its old tricks, Graham, who sits on the Senate Armed Services Committee, said doing so would be “a mistake.”

“If they don’t show up, that means diplomacy has failed and President Trump is intent on calling the question on North Korea in his first term,” he said. “So, that puts us back on the path to conflict. It would be time to take American families and dependents out of South Korea.”

Graham, who said he had spoken with Trump “two or three days ago,” claimed the North is “trying to run out the clock” despite Kim’s vague pledge late last month to “denuclearize the Korean Peninsula.”

“They have a record of promising to give up their nuclear weapons. In reality, they build up their weapons,” Graham said. “They’ve done this for 30 years. It’s going to end one way or the other by 2020.

“There’s no place to kick the can,” he added.

Still, it was unclear if Graham was dispatched in a kind of good-cop, bad-cop role in response to the North’s threats not to attend the summit. In Sunday’s interview, he maintained the administration’s stance that it was not aiming for regime change in Pyongyang.

“We’re not out to replace Kim Jong Un,” he said. “We’re not trying to reunify the peninsula. We’re not trying to spread democracy to North Korea.”

Asked about China’s role in resolving the nuclear issue, Graham said that the North would likely try to “play China against the United States.”

“They understand our electoral system and the only thing I can tell you after talking to President Trump three days ago, China and North Korea have a chance to end the conflict in a win-win fashion and if it doesn’t end soon, it’s going to be a real mess and if there’s a war, it will be in China’s backyard, not ours,” he said.

The senator’s hard-line stance on the issue is not the first time he has spoken about the possibility of war with the North.

In August, Graham stoked controversy when he said in an interview that Trump had told him that while a conflict would kill scores, it would be “over there” in Northeast Asia.

And in March, Graham also said that such a conflict would be “worth it in terms of long-term stability and national security.”

Responding to Graham’s March comments, Tommy Vietor, a national security council official in the administration of former President Barack Obama, wrote on Twitter at the time that the senator had “lost his god damn mind.”

Authorizing military action against North Korea raises the risk of escalation and miscalculation, including the potential use by the Kim regime of nuclear weapons against Japan, South Korea and possibly even the continental United States, with Kim viewing such a move as an attempt to wipe out his regime.

One estimate by the North Korea-watching 38 North website in October said that up to 2.1 million people in Tokyo and Seoul would die and another 7.7 million would be injured if Pyongyang attacked the two Asian capitals with nuclear weapons in response to U.S.-led military action.