US President Barack Obama has begun a visit to South Korea, amid rising tensions in the region over a rocket launch planned by the North.
Obama is to go to the volatile Demilitarised Zone between the two Koreas, before holding talks in Seoul.
The US has voiced concern that the rocket launch due in April is a pretext for a missile test but Pyongyang says it wants to put a satellite into orbit.
Obama will attend a security summit in Seoul tomorrow.
The conference will be attended by leaders from more than 50 nations.
Its main focus will be preventing criminal or militant groups from acquiring nuclear weapons.
North Korea is not taking part in the summit.