North Korea's newly launched satellite marks a "big deal" for Pyongyang, the crossing of a major threshold and a public relations win for the secretive country's new leader, Kim Jong Un, experts say.

The success, after years of failed attempts, triggered worries among world leaders about nuclear weapons, Iran and the balance of power in the Pacific.

U.S. Defense Secretary Leon Panetta called the launch "clear provocation."

Experts do not believe North Korea has a nuclear warhead small enough to fly on the kind of missile that Pyongyang has now proved it can send long-distance.

And the United States believes the North Koreans may not have full control of the satellite they launched into space Wednesday, according to one U.S. official who declined to be identified due to the sensitive nature of the information.

But the launch allowed the regime to flex its military and technological muscle on the world stage.

Panetta told CNN he is "very confident" that if North Korea were to launch a missile at the United States, the U.S. military could guard against it.

"Obviously the hope is that we never have to face that kind of threat," Panetta said. A central reason the United States is working to "rebalance the Pacific" is to deal with "the threat from North Korea," he added.

There is "a path for North Korea to end its isolation, but that requires abiding by its international obligations," White House spokesman Jay Carney said Wednesday. "... It has chosen not to, and therefore, there will be consequences for that."

Washington is leading the global response, threatening to impose sanctions on Pyongyang like those that have helped devastate Iran's economy.

Those efforts were under way Wednesday in Security Council meetings at U.N. headquarters in New York

"Members of the Security Council condemned this launch," the council said in a statement, calling it "a clear violation" of previous resolutions -- including one in April that demanded North Korea halt any launches using ballistic missile technology.

The council considers the issue urgent, the statement said.

Susan Rice, U.S. ambassador to the United Nations, called the statement one of the swiftest and strongest she had seen the council make about North Korea. "Now we go into the second phase" of discussions, she said: negotiations about what to do.

China and Russia, North Korean allies and two of the council's permanent members, could exercise their veto power.

The United States and other nations may impose unilateral measures, senior administration officials warned. But Pyongyang has ignored such threats before.

New U.N. sanctions are unlikely, but the council might step up pressure on North Korea in other ways, said George Lopez, a professor with the University of Notre Dame's Kroc Institute for International Peace Studies, who last year served on a U.N. panel of experts monitoring sanctions already in place against North Korea.

The council's sanctions committee could add more North Korean entities to the sanctions list, he said. It could also do more to enforce sanctions already in place, for example by increasing inspections of cargo leaving North Korea to ensure no weapons technology is being shipped out.

What the launch means

Wednesday's success was a breakthrough for the reclusive, nuclear-equipped state.

North Korea "could sell this technology to others, including Iran and Pakistan, who have been regular customers of North Korea's other missiles," warns Victor Cha, who analyzes the region for the Center for Strategic and International Studies.

"They still have other technological thresholds to cross (miniaturized warheads, reentry vehicle), but this was undeniably a major one."

The rocket blasted off from a space center on the country's west coast and delivered a satellite into its intended orbit, the North Korean regime said. The launch followed a botched attempt in April and came just days after Pyongyang suggested that a planned launch could be delayed.

North Korea's previous claims of successful launches have been dismissed by the United States and other countries.

But this time, a U.S. official confirmed that the object is in orbit. U.S. officials were looking into whether it is an operating satellite, the official said.