President Obama called North Korea’s launch of a three-stage rocket on Sunday a “provocative act” and called for a “strong international response” to address the threat of nuclear proliferation.

“North Korea broke the rules once again by testing a rocket that could be used for long range missiles,” Obama said in a speech in the Czech Republic on nuclear proliferation.

“This provocation underscores the need for action — not just this afternoon at the U.N. Security Council, but in our determination to prevent the spread of these weapons.”

Obama, traveling in Europe, called for international consensus to condemn the launch of what the North claimed was a satellite. The United States and others say it violates a U.N. ban on ballistic missile activity by the communist state even though the satellite failed to reach orbit.

While unsuccessful, the test was seen by many as an effort by North Korea to develop a long-range missile that could carry a nuclear warhead.

“With this provocative act, North Korea has ignored its international obligations, rejected unequivocal calls for restraint and further isolated itself from the community of nations,” Obama said.

“Rules must be binding. Violations must be punished. Words must mean something,” the president said. “The world must stand together to prevent the spread of these weapons. Now is the time for a strong international response ... now is the time for a strong international response, and North Korea must know that the path to security and respect will never come through threats and illegal weapons. All nations must come together to build a stronger, global regime. And that’s why we must stand shoulder to shoulder to pressure the North Koreans to change course.”

The U.N. Security Council met in emergency session Sunday afternoon at Japan’s request.

Susan Rice, the U.S. ambassador to the United Nations, said in an interview on ABC’s “This Week,” that the council “will be discussing the appropriate response. The United States believes ... the most appropriate response would a United Nations Security Council resolution.”

Later in the day, the Associated Press reported that, according to diplomats with knowledge of the talks, the council did not expect to reach agreement on a new resolution, possibly with tighter or added sanctions, until later in the week.

The goal is a unified response but it was likely that objections from Russia and China — the North’s closest ally — will almost certainly water down any strong response. Both have Security Council veto power.

In her appearance on “This Week,” Rice cited the UN’s 2006 resolution, “when the North Koreans launched a missile and the ... Security Council demanded a halt to future missile-related activity and any future missile launches.”

“We feel very strongly that what occurred today was a violation of that resolution,” she said. “So we will go back and work ... to both toughen existing regimes, but to add to that resolution.”