No major NKorean troop movements: US official

WASHINGTON: The United States has detected no major troop movements in North Korea or renewed work at a plutonium reprocessing plant despite rising tensions over Pyongyang's nuclear test, a US defense official said on Thursday. "We haven't seen any (movement of troops)," the official, who spoke on condition of anonymity, told media. But he added that tracking North Korea was always difficult as it remained "one of the most closed societies in the world." Seoul's defense ministry earlier said air and ground forces were keeping a closer watch on the land and sea border with the communist North after Pyongyang announced it was abandoning the armistice signed to end the Korean War in 1953. Tensions have mounted since the North on Monday tested a nuclear bomb and than test-fired five short-range missiles. Raising the "Watch Conditions" alert level for US and South Korean forces meant stepped up intelligence and surveillance efforts but no redeployment of American troops on the Korean peninsula, the defense official said. "This is a prudent step ... but it doesn't involve movement of forces," he said. The Pentagon has sought to play down the possibility of any US military action, referring reporters' questions about North Korea to the State Department. "This is something that's being handled through diplomatic means at this point," spokesman Bryan Whitman told reporters.