North Korea said Saturday it would invite foreign experts and journalists to observe a satellite launch which has sparked widespread condemnation and US threats that it could jeopardise food aid.

The Korean Committee for Space Technology "will invite experienced foreign experts on space science and technology and journalists" to observe the blast-off next month, the official news agency said.

The North announced Friday it would launch a long-range rocket carrying the satellite between April 12-16 to mark the 100th anniversary of the birth of its founding president Kim Il-Sung.

The United States, Japan, South Korea and the EU said the plan, announced just 16 days after Pyongyang agreed to suspend long-range missile tests in return for the US food aid, would breach a UN ban imposed after previous missile launches.

Pyongyang insists the programme is part of peaceful space research, while the US and other nations see it as a disguised missile test.

UN Security Council resolution 1874, passed after the North's missile launch and nuclear test in 2009, bans the country from carrying out any ballistic missile launches for any purpose.

The North's official news agency said it had told the International Civil Aviation Organisation, the International Maritime Organisation, the International Telecommunication Union and other bodies about the upcoming launch.

The main newspaper Rodong Sinmun said the rocket will take a "safer" flight path compared to previous launches that strayed into Japanese airspace.

The new flight orbit showcased the country's advancing "technological prowess" and "economic power", Professor Ko Yong-Hae from the Kim Il-Sung University wrote in the paper published Saturday.

Ko said 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".

The North's announcement appeared to jeopardise a February 29 agreement with the United States, which had raised hopes of eased tensions under new leader Kim Jong-Un.

The North agreed to suspend its uranium enrichment programme, along with long-range missile launches and nuclear tests, in return for 240,000 tonnes of much-needed US food aid.

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

And it voiced doubt over whether it could move ahead with providing the food aid if Pyongyang followed through with its threat.

"Were we to have a launch, it would create obviously tensions and that would make the implementation of any kind of nutritional agreement quite difficult," State Department spokeswoman Victoria Nuland said.

Nuland said that US diplomats told their North Korean counterparts prior to the February 29 agreement that a missile launch would be a "deal breaker".

South Korea and Japan condemned the plan. Russia also voiced concern and UN Secretary General Ban Ki-moon called on North Korea not to go ahead.

EU foreign policy chief Catherine Ashton said she was "deeply concerned" and called on the North to confirm that it will refrain from the launch "as a matter of urgency".

Even China, the North's closest ally, expressed concern.

Vice foreign minister Zhang Zhijun met Ji Jae-Ryong, Pyongyang's ambassador, on Friday to express Beijing's worries, the official Xinhua news agency said.

"We sincerely hope parties concerned stay calm and exercise restraint," Zhang was quoted as saying.

The North's 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 see them as a pretext for missile tests.

The North has said a Unha-3 rocket will launch a home-built polar-orbiting earth observation satellite. 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 as the young Kim tries to burnish his image as a strong leader.

The North said the rocket would be launched southward from a new site it has been developing at Tongchang-ri on 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.