** FILE ** South Korean soldiers stand at attention during ceremonies of the newly opened South Korean clinic inside the U.S. military base in Afghanistan, in this February 12, 2003, file photo. South Korea has begun preparations to pull its troops out of Afghanistan by the end of this year as scheduled, officials said Sunday July 22, 2007, amid a purported offer from the Taliban to swap 23 South Korean hostages for imprisoned Taliban fighters. The militant group had said that it would kill the South Koreans Saturday if Seoul didn't withdraw its troops from Afghanistan. But it later changed that demand, saying the Afghan and South Korean governments had until 7 p.m. (1430 GMT) Sunday to agree to the release of 23 Taliban militants or the Korean hostages would be killed. (AP Photo/Aaron Favila, FILE)