Washington ? North Korea’s announcement of a nuclear test was met Monday with worldwide condemnation, with the U.N. Security Council declaring the underground blast a “clear violation” of past resolutions and saying it would meet today to discuss possible steps against the regime.

President Obama described the test as a “blatant violation of international law,” and declared that the United States and other world powers “must take action in response.” The 15-member Security Council, which met for less than an hour, was expected in the coming days to consider a binding resolution criticizing North Korea’s nuclear weapon program. Some members have called for additional sanctions against the regime. But the question not answered Monday was what else the international community could do to motivate North Korea, which has pursued its nuclear program in the face of previous sanctions.

The test, which U.S. officials said had just more than 1 kiloton in force, was viewed in South Korea, Japan and some other countries as a more disturbing development than the regime’s first test in 2006, which was widely seen as a failure. Even so, it remained unclear how far countries that have influence with North Korea, such as China and Russia, would go in trying to punish the regime.

Although U.S. officials insisted that they had anticipated the test, it has come at a difficult time for the administration. Consumed by other foreign policy pressures, such as the wars in Afghanistan and Iraq, the Obama team has yet to develop its formal policy on North Korea. The administration doesn’t even have an assistant secretary of state for the region in place yet.

The test is the latest of a series of actions North Korea has taken since late last year to reject the international effort to ends its nuclear weapons program. The regime declared it was withdrawing from the six-country disarmament talks, tested a long range rocket, and expelled international nuclear inspectors.

U.S. officials said they expected world powers to pull together against the regime, but some acknowledged that the sanctions were not likely to cause North Korea quickly to change course, and that U.S. leverage is limited.

“What’s important is not as much what’s in the sanctions as the fact that there is unity,” one official said.

North Korea notified State Department officials after 7 p.m. Sunday that they planned a nuclear test. Obama was notified by his national security adviser, retired Gen. James Jones, at midnight, less than an hour after the test had taken place, U.S. officials said.

The United States and its allies may be able to enforce previous sanctions on military-related trade and luxury goods that have not been implemented or seek other U.N. and bilateral sanctions.

Even so, U.S. officials say that while they are intent on showing North Korea that there must be “consequences” for its actions, these steps are not likely to cause a change in North Korea’s course.

“The Obama administration has very few choices,” said Michael Green, head of Asian Affairs at the National Security Council under former President George W. Bush.