Seoul  - North Korean plans to launch a communications satellite in early April have aroused fears that the plan is really a cover for a test of an intercontinental ballistic missile.

South Korean media reported Thursday that North Korea has informed the International Maritime Organization (IMO) that it intends to launch a satellite between April 4 and 8. However, intelligence reports say the launch could really be a cover for a missile test.

Launching such a test would be a major leap forward for North Korea. Experts note that the technology needed to launch a satellite varies only slightly from that needed to launch a missile.

   Lee Adamson of the IMO said Thursday, speaking by telephone from London, said the UN agency had been notified of the planned launch of a Kwangmyongson-2 satellite.

   South Korea, the United States and Japan have all raised concerns about the North Korean plans. Seoul said the North has been preparing for weeks to launch a Taepodong-2 missile, potentially capable of carrying a nuclear warhead and reaching the United States.

In Washington, US State Department spokesman Robert Wood said a launch would be a "provocative act" and violate UN Security Council resolutions.

"The North needs to desist, or not carry out this type of provocative act," Wood said.

   North Korea's state-controlled Korean Central News Agency said Pyongyang had informed a shipping safety group, the International Civil Aviation Organization, and other international organizations of the upcoming launch, without mentioning a date for it.

   It said they had received the "necessary information" on the launch to protect ships and planes travelling in the area.

As part of its preparations for the launch, North Korea has also signed on to international treaties regulating the exploration of space.

   North Korea's army on Monday warned of retaliation if attempts were made to shoot down its satellite. Additionally, North Korea's army has put itself at the ready in response to joint US-South Korean military manoeuvres it says are threatening.

   It said in February that it was planning the launch of an "experimental communications satellite."

After a series of North Korean missile tests in July 2006, followed by a nuclear test that October, the United Nations called upon North Korea to suspend its missile programme. In the past, North Korea has fired a Taepodong-1 missile over Japan, but claimed it had only launched a satellite.