The United Nations Security Council has strongly condemned North Korea's third nuclear test and vowed to take action against Pyongyang.
The council statement was agreed at an emergency closed-door session convened by South Korea on Tuesday. The non-binding statement was approved by all 15 council members.
The United States, Britain, France, Russia and China - the five permanent members of the council - all condemned Pyongyang's latest nuclear test, which an international nuclear test monitoring agency in Vienna said was roughly twice as large as that of North Korea's 2009 nuclear test.
South Korean Foreign Minister Kim Sung-hwan, whose country is president of the council, said it would now consider "appropriate measures over the the "grave violation" of Security Council resolutions.
US Ambassador to the United Nations, Susan Rice, said Washington and its allies want the Security Council to pass a resolution that would "augment the sanctions regime" already in place due to Pyongyang's 2006 and 2009 atomic tests.
In Beijing, Chinese Foreign Minister Yang Jiechi on Tuesday summoned the North Korean ambassador to China to protest against the North's new nuclear test. Mr Yang said China was "strongly dissatisfied and resolutely opposed" to the test.
Several council diplomats said the United States and its allies would push for tough new sanctions rather than merely expanding existing measures imposed after Pyongyang's previous atomic tests, Reuters reports.
Diplomats say negotiations on new sanctions could take weeks since China is likely to resist tough new measures for fear that new sanctions could lead to further retaliation by the North Korean leadership.
Beijing has also been concerned that tougher sanctions could further weaken the North's economy and prompt a flood of refugees into China.