"It is a Chapter 7 mandatory resolution, and so I'm quite certain that China is going to live up to its responsibilities. But you cannot underestimate how big a blow it is to North Korea to have all of the neighbors now, including what has been its strongest supporter, China, fully united behind sanctions against its nuclear program," Secretary fo State Condolleezza Rice said.

China has signed on to a resolution that pledges cooperation in stopping the proliferation trade with North Korea.

 "And I'm quite certain that China has no interest in seeing the proliferation of dangerous materials from North Korea," the top US administration official maintained.

"This is the toughest action that China has ever signed on to vis-a-vis North Korea. The North Koreans now face a united front that will not allow them to continue to pursue their nuclear programs without consequence, and that's an extremely important step," Rice said.

"China, which has never wanted to impose sanctions, particularly on a state with which it has close relations, Russia, US, Japan, and the entire international community have now imposed the toughest sanctions on North Korea that have ever been imposed, done it unanimously," she said.

"It will allow efforts to prevent proliferation in the weapons of mass destruction that Kim Jong Il is brandishing, and it sends a very strong signal to North Korea that it is now completely isolated," she said.