The United States sent two B-2 stealth bombers "for a long-duration, round-trip training mission" from their US base to South Korea Thursday, dpa quoted its military command in Seoul as saying. The nuclear-capable bombers dropped "inert munitions" on a South Korean training ground, in a mission to demonstrate the US commitment and capability "to defend the Republic of Korea and to provide extended deterrence to our allies in the Asia-Pacific region," it said.