UNITED NATIONS: The U.N. Security Council strongly condemned North Korea’s third nuclear test Tuesday and vowed to take action against Pyongyang for an act that all major world powers, including traditional ally China, have denounced.

“The members of the Security Council strongly condemned this test, which is a grave violation of Security Council resolutions,” South Korean Foreign Minister Kim Sung-hwan, whose country is president of the council this month, told reporters. He said the council would now consider “appropriate measures.”

The non-binding statement was approved by all 15 council members.

U.S. Ambassador to the United Nations Susan Rice said that Washington and its allies want the Security Council to pass a resolution that would “augment the sanctions regime” already in place as a result of Pyongyang’s 2006 and 2009 atomic tests.

The council statement was agreed at an emergency closed-door session convened by South Korea.

Diplomats say negotiations on new sanctions could take weeks since China is likely to resist tough new measures out of fear that new sanctions could lead to further retaliation by North Korea’s leadership.

Beijing has also been concerned that tougher sanctions could further weaken the country’s economy and prompt refugees to flood into China.

The United States, Britain, France, Russia and China – the five permanent members of the 15-nation council – all condemned Pyongyang’s latest trial, which an international monitoring agency in Vienna said was roughly twice as large as North Korea’s 2009 nuclear test.

U.S. President Barack Obama said “the danger posed by North Korea’s threatening activities warrants further swift and credible action by the international community.”

Several diplomats said Obama’s annual State of the Union address later Tuesday was a possible reason why North Korea chose this day to detonate an atomic device, since Pyongyang traditionally makes such moves on important days in the U.S. calendar.

China’s reaction was more muted. In Beijing, Chinese Foreign Minister Yang Jiechi Tuesday summoned the North Korean ambassador to China to protest against the new nuclear test.

Yang said China was “strongly dissatisfied and resolutely opposed” to the trial.

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 2006 and 2009 atomic tests.

It was not clear what measures, if any, China would support. Diplomats said the Chinese delegation indicated behind closed doors that it could support a new council resolution on North Korea but did not specify what it would allow to be in it.

When North Korean leader Kim, 30, took power after his father’s death in December 2011, there were hopes that he would bring about reforms and end Kim Jong Il’s “military first” policies.

China has long made clear its opposition to a new North Korean nuclear test, but council diplomats say Beijing could be expected to put up some initial resistance to new U.N. sanctions.

U.N. diplomats predicted, China will most likely eventually approve some form of punitive measures against North Korea, although it was not clear how harsh they will permit them to be.

Victor Cha of the Center for Strategic and International Security in Washington said “Chinese leaders cannot be happy with this test.”

In January the council passed a resolution expanding existing U.N. sanctions against North Korea due to a December rocket launch and warned Pyongyang against further such actions or nuclear tests. North Korea responded by threatening a new atomic detonation.

North Korea’s previous nuclear tests prompted the Security Council to impose sanctions – including a ban on the import of nuclear and missile technology, an arms embargo and a ban on luxury goods imports – on the impoverished authoritarian state.

There are 17 North Korean entities, including banks and trading companies, on the U.N. blacklist, as well as nine individuals – all linked to North Korea’s nuclear and missile programs. U.N. diplomats say many more entities and individuals could be subject to international asset freezes and travel bans.

U.N. Secretary-General Ban Ki-moon, a former South Korean foreign minister, said in a statement that he hoped the Security Council would take appropriate action.

“It is deplorable that Pyongyang defied the strong and unequivocal call from the international community to refrain from any further provocative measures,” he said.

He later told the council that “the authorities in Pyongyang should not be under any illusion that nuclear weapons will enhance their security.

“To the contrary,” he added, “as Pyongyang pursues nuclear weapons it will suffer only greater insecurity can isolation.”