SEOUL: Conversations have begun between the United Nations Command and North Korea over the case of U.S. soldier Travis King who crossed into the North, the deputy commander of the U.S.-led multinational command that oversees the Korean War truce said on Monday.

The conversation had been initiated and were being conducted with North Korea's military through a mechanism established under the Korean War armistice, U.N. Command deputy commander, Lieutenant General Andrew Harrison, told a briefing.

"The primary concern for us is private King's welfare," he said.

King, a U.S. Army soldier serving in South Korea, sprinted into North Korea on Tuesday while on a civilian tour of the Demilitarized Zone on the border between the two Koreas.