In a tiny mess hall set amid pine trees and rose bushes on the heavily fortified border between South and North Korea, a lunch of steak and asparagus is served. Outside, bird song competes with the drone of North Korean loudspeakers blaring propaganda.

"This is the best restaurant in the DMZ," says Major General Mats Engman, who heads the Swedish delegation to the Neutral Nations Supervisory Commission (NNSC), set up after the 1950-53 Korean War to uphold a fragile armistice in place of a peace treaty.

Originally a four-nation commission including representatives on the North Korean side from Poland and the former Czechoslovakia, only the Swedes and Swiss remain, based in 1950s-era huts just meters from North Korea.