Awwal 25, 1432, Feb 28, 2011, SPA -- South Korean and U.S. troops began annual military drills Monday that North Korea warned could trigger a war on the divided peninsula, the Associated Press reported. About 12,800 U.S. troops and some 200,000 South Korean soldiers and reservists are to participate in the drills, which are aimed at defending South Korea and responding to any attack. The main part of the drills, which will involve computer war games and live-firing exercises, will last 11 days, while some field training will continue until late April, according to the South Korea-U.S. joint forces command in Seoul. The drills «are planned months in advance, and they are not connected to any current world events,» the joint command said in a statement.