U.S. urges China to pressure North Korea after nuclear test

By Phil Stewart OSLO (Reuters) - The United States called on China to put pressure on North Korea to end its nuclear program after Pongyang conducted its fifth and biggest nuclear test on Friday. U.S. Defense Secretary Ash Carter, on a visit to Norway, also reaffirmed an "iron-clad" commitment to defend South Korea and condemned the North Korean test as a direct challenge to the entire international community. Carter said the international community should redouble pressure on North Korea after