President Donald Trump said the U.S. was open to joining discussions with South Korea and North Korea at “the appropriate time,” and that he would be willing to speak directly with Kim Jong Un under the right conditions.

“Right now, they’re talking Olympics. It’s a start. It’s a big start,” Trump said at a news conference at Camp David about talks expected Tuesday between South Korea and North Korea. It would be “great for humanity” if something beyond cooperation in next month’s Winter Olympic Games resulted, he said.

When asked whether he would be open to talking with the North Korean leader, whom he has dismissed in Twitter messages and in a United Nations speech as “Rocket Man,” Trump said, “Sure, I always believe in talking,” adding that “he knows I’m not messing around, not even a little bit.”

Trump’s openness to talks recalled his more accommodating approach during the 2016 campaign, when he said he could negotiate with Kim over a hamburger. More recently, he had dismissed diplomatic efforts, even publicly chiding U.S. Secretary of State Rex Tillerson in October for “wasting his time” by pursing them.

Bigger Button

In August, Trump vowed to unleash “fire and fury” if North Korea threatened the U.S. and on Tuesday warned Kim on Twitter that his nuclear button was “much bigger and more powerful.” Trump argued Saturday that talks wouldn’t be possible without his tough rhetoric.

“These are constructive comments by the president,” said Nicholas Burns, a former undersecretary of state under President  Bush. “It is essential that we remain united with Seoul and not permit Kim Jong Un to divide us.”

North Korea and South Korea remain technically at war more than six decades after open hostilities ceased, with more than 30,000 American troops and the U.S. nuclear umbrella pledged to Seoul’s defense. Kim’s offer of reconciliation could strain that alliance by drawing South Korean President Moon Jae-in away from the U.S. bottom line.

Foreign Powers

Moon campaigned on greater engagement with North Korea and has since his May election affirmed his commitment to reunification through dialogue. He quickly accepted Kim’s New Year’s Day offer of talks, even though the North Korean leader also pledged to increase weapons production. The Trump administration had said that Kim must at least pause his nuclear weapons program before talks would be considered.

A commentary published by the state-run Korean Central News Agency  described improved ties with Seoul as a “crucial matter,” departing from its usually dismissive tone toward the South. The commentary warned that “depending on foreign powers” risked complicating talks.

Still, both the U.S. and South Korea want no disruptions during the Oly­mpics in Pyeongchang, about 50 mi­les from the heavily fortified border between the two Koreas. At Moon’s request, Trump delayed annual joint U.S.-So­uth Korean military exercises — long a source of consternation to the North — until after the Paralympic Games conclude on March.

“The only thing they’re talking about in this discussion coming up, according to the South Koreans, who will be engaged in directing that, is the Olympics,” U.S. Secretary of Defence James Mattis told reporters  “There’s nothing where they can drive a wedge at all.” North Korean Olympic representative Chang Ung was expected to meet International Olympic Committee officials in Switzerland this week to discuss his country’s participation in the event, South Korea’s Yonhap News Agency reported, citing unidentified people. Chang told reporters Saturday at Beijing Capital International Airport that a pair of North Korean figure skaters were likely to compete, Japan’s Kyodo News reported.