North Korea said Tuesday that it plans to launch a satellite-carrying rocket as soon as next week, a move that could demonstrate potential progress in the nation’s long-running mission to develop a reliable intercontinental ballistic missile.

The North gave notice of the launch — which it said would come between Feb. 8 and Feb. 25 — in an alert to the International Maritime Organization, a group responsible for maritime safety.

Although North Korea has described its satellite program as peaceful, the launches rely on long-range missile technology and defy sanctions designed to restrict the country’s weapons program. A launch coming just four weeks after an underground nuclear test would sharpen concern in the West and across Asia that Pyongyang is attempting to make progress on its ultimate goal — the ability to fire off a miniaturized nuclear warhead with an accurate ballistic missile.

In Washington, the State Department official in charge of East Asian affairs, Daniel Russel, said the purported launch plans “argue even more strongly” for tougher U.N. sanctions on the North.

The United States has led calls for additional measures by the U.N. Security Council in response to last month’s nuclear test, the North’s fourth since 2006. But North Korean leader Kim Jong Un, during his four years in power, has repeatedly signaled that he is willing to test weapons technology in defiance of the international community. Under Security Council resolutions, the North has long been prohibited from launching rockets using “ballistic missile technology.”

White House spokesman Josh Earnest described North Korea's publicized plans to launch a satellite as "an irresponsible provocation" and "a clear violation of their international obligations," at a briefing on Feb. 2. (Reuters)

In an apparent reference to China, Pyongyang’s ally, which has resisted the expansion of sanctions, Russel also said the planned rocket launch “would be an unmistakable slap in the face” to those who have backed “patience and dialogue” with the North rather than sanctions.

[China backs U.N. move to denounce North Korea over nuclear test]

North Korea’s official news agency has provided no details on the planned launch, which would be the authoritarian nation’s fifth, dating back to 1998. But the announcement came as little surprise to outside analysts: Recent satellite imagery had shown a flurry of activity at the North’s launch site, in the northwestern corner of the country.

In recent years, the North has used nuclear and missile tests as headline events for political celebrations, and some experts said the latest launch could serve as a showcase of might for the Feb. 16 birthday of former leader Kim Jong Il. Still, there is no guarantee of success: Of the North’s five launches, only the most recent one, in December 2012, reached orbit. And even that satellite appeared to malfunction days or hours after reaching space, said Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics.

“If it worked, it didn’t work for long,” McDowell said.

Over the past two years, North Korea has taken steps to upgrade its launch facility, extending the launch tower to accommodate higher-powered rockets. Models of a larger rocket, known as Unha-9, have been displayed at various events across the country.

Yet the North still faces many hurdles, and experts said Tuesday that this launch would be technologically similar to previous ones. Pyongyang’s latest maritime notice suggests that the first stage of the rocket will fall into the waters between South Korea and China; the second stage will plummet east of the Philippines. Those potential drop zones look much as they did in 2012 — suggesting a rocket of similar design, experts said.

“This looks very similar to what they did a couple years ago,” said Jeffrey Lewis, a nuclear expert at the Middlebury Institute of International Studies. “Ultimately, we’re talking about an observation satellite. If it works, maybe they’ll end up with some pictures they show. And if it doesn’t work, they’ll just fake some pictures.”

[North Korea claims sub-based missile launch]

There is still broad disagreement among analysts and intelligence experts about North Korea’s weapons capability. For Pyongyang to directly threaten the United States, it must be able to miniaturize a nuclear weapon — and hone the technology that would allow a rocket to reenter the atmosphere from space.

In 2013, the Defense Intelligence Agency said that North Korea had the capability to mount a miniaturized warhead on a long-range missile, although the reliability of such a weapon would be “low.” But Director of National Intelligence James R. Clapper Jr. quickly played down that assessment, saying that Pyongyang had “not yet demonstrated the full range of capabilities necessary for a nuclear armed missile.” The North itself has claimed that it has the ability to create small nuclear weapons suitable for missiles.

According to the North, two of its earliest satellites — from 1998 and 2009 — are in orbit, transmitting revolutionary songs. Experts dispute that, saying the launches failed.

After a botched launch in April 2012, the North, in a rare moment of transparency, told its people that the satellite had “failed to enter” space and that scientists were “looking into the cause.”

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