President Donald Trump is on his way to the Korean Demilitarized Zone for a historic meeting with North Korea's Kim Jong Un.
Trump departed Seoul by helicopter on Sunday afternoon shortly after South Korean President Moon Jae-in announced that Kim had accepted Trump's invitation to meet at the heavily fortified site at the Korean border village of Panmunjom.
The meeting is set to mark yet another historic first in the yearlong rapprochement between the two technically warring nations.
It also marks the return of face-to-face contact between the leaders since negotiations to end the North's nuclear program broke down during a summit in Vietnam in February.
Presidential visits to the DMZ are traditionally carefully guarded secrets for security reasons.
Trump claimed before flying from Japan to South Korea that he wasn't even sure Kim was in North Korea to accept the invitation.
"All I did is put out a feeler, if you'd like to meet," Trump said in Japan.
He added, somewhat implausibly: "I just thought of it this morning."
Before arriving in Seoul, Trump said at a news conference in Japan that he'd "feel very comfortable" crossing the border into North Korea if Kim showed up, saying he'd "have no problem" becoming the first U.S. president to step into North Korea.
His comments followed hours after Trump asked Kim to meet him there. "If Chairman Kim of North Korea sees this, I would meet him at the Border/DMZ just to shake his hand and say Hello(?)!" he tweeted.
It was not immediately clear what the agenda, if any, would be for the potential third Trump-Kim meeting.
"It's just a step. It might be an important step but it might not," Trump said.
Such a spectacle would present a valuable propaganda victory for Kim, whose family has long been denied the recognition it sought on the international stage.