SEOUL, South Korea - The U.S. military will relinquish a key outpost along the tense frontier with North Korea this year as part of a force reshuffle on the divided Korean Peninsula, a U.S. military official said Tuesday.

The turnover of Observation Post Ouellette, a dusty crag with a view deep into North Korea, means that U.S. troops will no longer patrol the tense border, except for a small contingent at the truce village of Panmunjom.

Duties along the heavily fortified buffer area, called the Demilitarized Zone, will be handed over to South Korea, which has a 600,000-member military staring off against North Korea's armed forces, the world's fifth largest with 1.1 million soldiers.

The 2½-mile wide, 151-mile long DMZ - a Cold War vestige strewn with mines and laced with barbed wire and tank traps - separates the two sides.

U.S. troops guarding the inter-Korean border are often regarded as a "tripwire" because they are presumed to come under fire during a North Korean attack, thereby prompting U.S. intervention.

The United States has about 37,000 troops stationed in South Korea, but has long kept fewer than 200 soldiers along the DMZ, at Observation Post Ouellette and Panmunjom, said U.S. Air Force Lt. Col. Deborah Bertrand.

Details on the timing of Ouellette's turnover and the eventual troop level at Panmunjom are still being decided in consultation with South Korea, Bertrand said, adding: "It will be this year."

U.S. Gen. Leon J. LaPorte, joint commander of the U.S. Forces Korea and the United Nations Command overseeing the cease fire that ended the 1950-53 Korean War, told the U.S. Congress last month that the changes were meant to give South Korea a greater role in defending itself.

He said the "Republic of Korea will replace all United States personnel directly involved along the DMZ," except for Panmunjom, where the United States will maintain command over a battalion of joint U.S.-South Korean forces.

The United States is currently reviewing its military posture in South Korea as part of a global realignment to make its forces more nimble and technology-driven.