"Getting ready to leave for South Korea and meetings with President Moon, a fine gentleman," Trump tweeted early on Tuesday from Japan, the first stop of his Asian tour, adding: "We will figure it all out!"
Trump flies in from Japan after securing Tokyo’s full support for Washington’s stance that "all options are on the table" regarding Pyongyang, and declaring its nuclear ambitions "a threat to the civilised world and international peace and stability".
He enjoyed three days of near-bromance with Prime Minister Shinzo Abe, calling him "wonderful" after a round of golf and describing US-Japan ties as "really extraordinary".
South Korea will roll out the red carpet for Trump as it seeks messages of assurance about the alliance and US resolve.
At the same time, while Trump has threatened Pyongyang with "fire and fury", Moon is mindful that much of Seoul is within range of the North’s artillery and in an address to parliament last week demanded: "There should be no military action on the peninsula without our prior consent."
Another issue will be trade between the two nations, with Trump expected to bring up the renegotiation of the five-year-old US-Korea free trade agreement which he has called a "horrible deal" and a "job killer".
His first stop in the South will be Camp Humphreys, where US forces stationed in the country have moved their headquarters from downtown Seoul.
Later he will have a summit with Moon at the Blue House, followed by a lavish dinner with live concerts by both Korean traditional musicians and K-pop artists.
On Wednesday, Trump will speak to South Korean MPs but his visit will not include a trip to the Demilitarised Zone dividing the Korean peninsula, with the administration downplaying the destination as "a little bit of a cliche".
Some observers have fretted that a gaffe by a president given to off-the-cuff remarks could send tensions rising on the peninsula.
"If Trump says anything that can provoke North Korea, it could send military tensions soaring again," said professor Koo Kab-Woo from the University of North Korean Studies in Seoul. BY VIETNAMNEWS.