President Barack Obama visited the border between North and South Korea on Sunday.
It was a show of solidarity with Seoul, a big U.S. ally, and a message of resolve to Pyongyang, a day before a nuclear summit in South Korea.
Obama peered through binoculars from behind a bullet-proof glass in an observation deck.
He spent 10 minutes at the border and greeted troops stationed there.
The 4-kilometre long DMZ is one of the most heavily fortified borders in the world.
The tour bristled with Cold War symbolism - coming amid rising concern over plans by North Korea to launch a rocket next month. The rocket launch threatens to derail a deal with the U.S. to resume food aid to the impoverished state.
Michaela Cabrera, Reuters.