US urges China, Russia to do more to restrain N. Korea

The United States on Tuesday called on China and Russia to do more to rein in North Korea, after Pyongyang announced it would restart a nuclear reactor to feed its atomic weapons program.

White House spokesman Jay Carney said the North's decision to reopen its Yongbyon reactor -- its source of weapons-grade plutonium -- was "another indication" of Pyongyang "violating its international obligations."

"It is not a mystery to anyone that China has influence with North Korea," Carney told reporters.

"We have in the past and are now urging China to use that influence to try to affect North Korean behavior. That is also true of our (conversations) with the Russians."

Beijing has already voiced regret over North Korea's announcement, appealing for calm on the Korean peninsula.