The Stalinist state announced the moratorium in September 1999, one year after it sparked global concern by test-launching a Taepodong-1 missile with a range of 2,500 kilometres (1550 miles) over Japan.

North Korea said the moratorium was agreed when dialogue was under way with the former US administration of Bill Clinton. It said current US President George W. Bush had cut off talks when he took office in 2001, making the moratorium invalid.

"Accordingly, we are not bound to the moratorium on the missile launch at present," said a 5,000-word foreign ministry statement explaining why North Korea is boycotting new six-nation talks on its nuclear weapons programs.

"As everybody knows, the US hostile policy toward (North Korea) compels it to bolster its self-defensive nuclear arsenal," said the statement carried by the official KCNA news agency.

US officials say North Korea's missile program poses a serious threat to the United States and its allies. North Korea's missile launch in 1998 prompted Japan to begin researching missile defense.

Deputy US State Department spokesman Adam Ereli said Wednesday any North Korean threat to test missiles would undermine the framework the six-nation talks process, which is aimed at dismantling North Korea's nuclear arsenal.

"As far as threats to undertake tests or other military activity, that certainly is not helpful and doesn't serve a useful purpose. And I think it's not consistent with the spirit of the six-party talks," he said.

South Korea's intelligence agency says North Korea is developing rocket engines for its Taepodong-2 missile with a range of 6,700 kilometersmiles), which would be capable of hitting the US state of Hawaii.

However it says North Korea lacks the technology to launch a nuclear-tipped missile.

CIA Director Porter Goss told the US Congress last month that nuclear-armed North Korea could resume missile tests anytime and that it has active biological and chemical weapons programs.

North Korea on February 10 announced it possessed nuclear weapons and was withdrawing indefinitely from the six-party talks.

The two Koreas, the United States, China, Japan and Russia, have met three times since 2003, with the last round held in June. North Korea boycotted a fourth round scheduled for last September, citing "hostile" US policy.

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.