SEOUL, March 3: North Korea on Thursday ended a self-imposed moratorium on testing long-range missiles and said "hostile" US policy was forcing it to develop its nuclear arsenal, prompting immediate condemnation from Japan.

The moratorium was announced in September 1999 - one year after it sparked global concern by test-launching a missile over Japan. North Korea said it 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 programmes.

"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.

The announcement came a day after North Korea, a self-proclaimed atomic power, demanded the US apologize for calling it part of an "axis of evil" and one of the "outposts of tyranny" before it would return to the talks.

Japan, which neighbours North Korea across the East Sea (Sea of Japan), quickly condemned the latest statement.

"North Korea is trying to raise the stakes by stirring tension ahead of the six-way nuclear talks," an official in the foreign ministry's Northeast Asia division said on condition of anonymity.

"It is unproductive," he said. "Japan, South Korea and the United States continue to work toward a resumption of six-way talks without any conditions."

The latest North Korean bombshell - which on February 10 announced it was pulling out of the talks indefinitely and had manufactured nuclear weapons - came as diplomacy continued to bring it back to the table.

China's top nuclear envoy, Vice Foreign Minister Wu Dawei, and US Ambassador to Seoul Christopher Hill, who heads Washington's negotiating team to the talks, met at the US embassy in Seoul.

US officials refused to give details on the meeting but Hill later told a seminar that the United States would only address North Korean demands at the negotiating table.

"We will be prepared and we have been prepared to deal with any questions and deal with the DPRK (North Korea), but at the table," he said at a seminar. The UN's atomic agency on Thursday also urged Pyongyang back to nuclear talks.

In a statement adopted by consensus, the International Atomic Energy Agency's (IAEA) 35-nation board of governors "expressed its serious concern" at North Korea's decision to abandon the six-way talks.

The statement "urged particularly the DPRK to agree to the resumption of the six-party talks... without preconditions." The State Department brushed off the demand for an apology for Bush's 2002 description of North Korea as part of an "axis of evil" and Secretary of State Condoleezza Rice's comment in January that it was one of the world's "outposts of tyranny". -AFP