North Korea successfully fired a long-range rocket on Wednesday, defying international warnings as the regime of Kim Jong Un took a giant step forward in its quest to develop the technology to deliver a nuclear warhead.

The United States, South Korea and Japan quickly condemned the morning launch, which came as something of a surprise after Pyongyang had indicated technical problems might delay it. That it succeeded after several failed attempts was an even greater surprise.

The regime's stated purpose for firing its long-range Unha-3 rocket was to put a peaceful satellite into orbit, but the United Nations, as well as the U.S. and its allies see it as cover for a test of technology for missiles.

About two hours after the launch, North Korea's state media proclaimed it a success, prompting celebrations across the capital. The North American Aerospace Defense Command, or NORAD, later confirmed that North Korea did appear to have put an object into space.

Wednesday's launch is likely to bring fresh sanctions on the North, and the White House called it a "highly provocative act that threatens regional security."

NORAD said the rocket traveled south with the first stage falling into the Yellow Sea and a second stage falling into the Philippine Sea hundreds of kilometers (miles) farther south. "Initial indications are that the missile deployed an object that appeared to achieve orbit," NORAD said in a statement.

Japan protested the launch and said one part of the rocket landed west of the Korean Peninsula, and the Philippines said another part landed 300 kilometers (186 miles) east of its shores. South Korean President Lee Myung-bak held an emergency national security council meeting Wednesday, and South Korean Foreign Minister Kim Sung-hwan warned that North Korea will face grave consequences.

Japan's Foreign Ministry said Tokyo immediately requested consultations on the launch within the U.N. Security Council. The council will hold closed-door consultations on the launch Wednesday at the request of one council member and two other countries, according to the U.N. Mission for Morocco, which holds the rotating council presidency.

A similar North Korean launch in April broke apart shortly after liftoff.

"Clearly this is much more successful than their last attempt," said Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics. "It's at least as good as they've ever done. They've proved the basic design of it."

He said success would be defined as "something that completes at least one orbit of the Earth."

Rocket tests are seen as crucial to advancing North Korea's nuclear weapons ambitions. North Korea is thought to have only a handful of rudimentary nuclear bombs. But Pyongyang is not yet believed capable of building warheads small enough to mount on a missile that could threaten the United States.

North Korea has spent decades trying to perfect a multistage, long-range rocket. Experts say that ballistic missiles and rockets in satellite launches share similar bodies, engines and other technology. This is the fifth attempt at a long-range launch since 1998, when Pyongyang sent a rocket hurtling over Japan. Previous launches of three-stage rockets weren't considered successful.

North Korea under new leader Kim has pledged to bolster its nuclear arsenal unless Washington scraps what Pyongyang calls a hostile policy.

Kim took power after his father Kim Jong Il died on Dec. 17 last year, and the launch is seen by some as an attempt to commemorate that. It also comes less than a week before presidential elections in South Korea and about a month before President Barack Obama is inaugurated for his second term.

North Korean television and radio broadcast word of the successful launch and there were vehicles with loudspeakers driving around Pyongyang announcing the news. Customers in the coffee shop at Pyongyang's Koryo Hotel broke into applause during a special television broadcast, while elsewhere people danced and asked each other: "Have you heard the news?"

The launches Wednesday and in April came from a site on the west coast, in the village of Tongchang-ri, about 56 kilometers (35 miles) from the Chinese border city of Dandong, across the Yalu River from North Korea. The site is 70 kilometers (45 miles) from the North's main Yongbyon nuclear complex, and is said to have better roads and facilities than previous sites and to allow a southerly flight path meant to keep the rocket from flying over other countries.

Tensions are high between the rival Koreas. The Korean Peninsula remains technically at war, as the 1950-53 conflict ended in a truce, and Washington stations nearly 30,000 troops in South Korea as a buttress against any North Korean aggression. Tens of thousands more are in nearby Japan.