North Korea announced Friday it would launch a rocket carrying a satellite next month, just 16 days after agreeing to suspend long-range missile tests in return for massive US food aid.

The United States, Japan and South Korea condemned the plan and said it would breach a United Nations ban imposed after previous launches.

Blast-off will be between April 12 and 16 to mark the 100th anniversary of the birth of founding leader Kim Il-Sung, the communist state's official news agency and state television said.

The US State Department called the proposed launch "highly provocative" and a threat to regional security.

It would also be inconsistent with the announced missile test moratorium, spokeswoman Victoria Nuland said in a statement.

The surprise February 29 deal, under which Pyongyang also promised to freeze its uranium enrichment plant, had raised hopes of eased tensions under the new regime headed by Kim Jong-Un.

But one analyst said Friday's announcement effectively killed off the agreement, under which the US was to give the hungry and impoverished nation 240,000 tonnes of food over a year.

The last long-range rocket launch on April 5, 2009, also purportedly to put a satellite into orbit, brought UN Security Council condemnation and tightened sanctions.

Pyongyang quit six-party nuclear disarmament talks in protest at the censure and conducted its second atomic weapons test the following month.

The North insists its satellite launches are for peaceful scientific purposes while the US and other nations call them disguised missile tests.

UN Security Council Resolution 1874, passed after the North's second nuclear test, demands that it "not conduct any further nuclear test or any launch using ballistic missile technology".

South Korea's foreign ministry said any launch would breach the resolution and be a "grave, provocative act".

Japan, whose airspace was overflown by the 2009 rocket, also said a launch would violate UN decrees and it would "strongly demand self-restraint".

China, the North's main economic benefactor, urged "all parties to play a constructive role" in keeping peace on the peninsula.

The North said a Unha-3 rocket will launch a home-built polar-orbiting earth observation satellite known as Kwangmyongsong-3.

Repeating its arguments of 2009, it said such satellites assist economic development and are in line with the peaceful use of space.

The launch "will greatly encourage the army and people... in the building of a thriving nation", it added, as it prepares a mass celebration for the April 15 centenary and the young Kim tries to burnish his image as a strong leader.

"A safe flight orbit has been chosen so that carrier rocket debris to be generated during the flight would not have any impact on neighbouring countries," it said.

The North said the rocket would be launched southward from a new site it has been developing at Tongchang-ri in the northwest tip of the country.

The Unha-3 is known outside the North as the Taepodong-3 and is theoretically capable of reaching US territory, said Baek Seung-Joo of the Korea Institute for Defence Analyses.

"Following the alleged satellite launch attempt in 2009, this is another ploy to heap pressure on the United States by conducting a test-launch of a rocket which can easily be converted to weapons use," said Yang Moo-Jin of Seoul's University of North Korean Studies.

"It also wants to show off to the world it has become a strong state with technological and military prowess as it enters a new era under Jong-Un and marks the 100th anniversary of Kim Il-Sung," Yang told AFP.

Kim Jong-Un is Kim Il-Sung's grandson. He took over the leadership after his own father Kim Jong-Il died on December 17.

Kim Yong-Hyun, of Seoul's Dongguk University, said the North would insist its launch was for peaceful scientific purposes and unrelated to the missile test moratorium.

"The US will, of course, make a strong response, regarding it as a long-range missile launch," he told AFP, adding it was unclear whether it would derail negotiations.

But Daniel Pinkston, Seoul-based analyst with the International Crisis Group, said the announcement means the February agreement with the United States "is pretty much dead".

Such rockets, he told AFP, are "inherently dual-use technology: if you can launch a satellite you can deliver a warhead at long range".

The launch will come just after South Korea's April 11 general election. The North bitterly opposes the ruling conservative party, which scrapped the aid and engagement policy of previous liberal governments.

Chronology of North Korean missile development
Seoul (AFP) March 16, 2012 - North Korea announced Friday it would launch a long-range rocket next month to put a satellite into orbit, a move that would breach a United Nations ban imposed after previous launches.

These are key dates in its missile programme:

Late 1970s: Starts working on a version of the Soviet Scud-B (range 300 km or 187 miles). Test-fired in 1984

1987-92: Begins developing variant of Scud-C (500 km), Rodong-1 (1,300 km), Taepodong-1 (2,500 km), Musudan-1 (3,000 km) and Taepodong-2 (6,700 km)

Aug 1998: Test-fires Taepodong-1 over Japan as part of failed satellite launch

Sept 1999: Declares moratorium on long-range missile tests amid improving ties with US

July 12, 2000: Fifth round of US-North Korean missile talks ends in Kuala Lumpur without agreement after North demands one billion dollars a year in return for halting missile exports

Dec 2002: Fifteen North Korean-made Scuds seized on Yemen-bound ship

March 3, 2005: North ends moratorium on long-range missile testing, blames Bush administration's "hostile" policy

July 5, 2006: North test-fires seven missiles, including a long-range Taepodong-2 which explodes after 40 seconds

July 15, 2006: UN Security Council adopts Resolution 1695, demanding halt to all ballistic missile activity and banning trade in missile-related items with the North

Oct 9, 2006: North conducts underground nuclear test, its first

Oct 14, 2006: Security Council approves Resolution 1718, demanding a halt to missile and nuclear tests. Bans the supply of items related to the programmes and of other weapons

April 5, 2009: North Korea launches long-range rocket which flies over Japan and lands in the Pacific, in what it says is an attempt to put a satellite into orbit. The United States, Japan and South Korea see it as a disguised test of a Taepodong-2

April 13, 2009: UN Security Council unanimously condemns launch, agrees to tighten existing sanctions. North quits nuclear disarmament talks in protest and vows to restart its plutonium programme

May 25, 2009: North conducts its second underground nuclear test, several times more powerful than the first

June 12, 2009: Security Council passes Resolution 1874, imposing tougher sanctions on the North's atomic and ballistic missile programmes

July 4, 2009: North test-fires seven ballistic missiles off its east coast

Feb 18, 2011: Satellite images show the North has completed a launch tower at its new west coast missile base at Tongchang-ri, experts say

May 15, 2011: North Korea and Iran are suspected of sharing ballistic missile technology, according to a UN sanctions report, diplomats say

March 16, 2012: North Korea announces it will launch a long-range rocket between April 12-16 to put a satellite into orbit