OSLO The United States called on China to put pressure on North Korea to end its nuclear programme 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 the test, on the 68th anniversary of North Korea's founding, and singled out China's influence.
"It's China's responsibility," he told a news conference. "China has and shares an important responsibility for this development and has an important responsibility to reverse it."
"And so it's important that it (China) use its location, its history and its influence to further the denuclearisation of the Korean peninsula," he said.
Under 32-year-old leader Kim Jong Un, North Korea has accelerated the development of its nuclear and missile programmes, despite U.N. sanctions that were tightened in March and have further isolated the impoverished country.
Carter said the nuclear test would strengthen resolve to bolster defences in South Korea, including deployment of U.S. THAAD anti-missile units and radars.
He said he spoke with South Korean Defence Minister Han Min-koo after the test and "reaffirmed our iron-clad commitment to the defence of South Korea and our other allies in the region".
(Reporting By Philip Stewart, editing by Alister Doyle)