World alarmed as N Korea threatens nuclear test

"A missile test launch would be viewed by the United Kingdom and the rest of the international community as a highly provocative act with serious consequences for the DPRK," said a spokesman for the British Foreign Office.

"It would raise tensions in an already tense region," he added.

Pyongyang said Tuesday that it intended to carry out a test of nuclear weapons in response to threats and sanctions from the United States which it said was trying to topple the communist nation.

"The US extreme threat of a nuclear war and sanctions and pressure compel the DPRK (North Korea) to conduct a nuclear test, an essential process for bolstering nuclear deterrent, as a corresponding measure," it said.

The statement, issued by the foreign ministry, gave no time or date for the test, which if carried out would be the first anywhere in the world since 1998.

Japan was first to respond to the announcement, with Foreign Minister Taro Aso denouncing the idea as unforgivable.

"It would be a threat to peace. We would never be able to forgive such a move," Aso told reporters. "It would gravely affect Northeast Asia, including Japan."

Aso said he did not doubt North Korea's resolve in testing a nuclear device.

"In the past, the country has done what it had said earlier. So I think it would be wrong automatically to think the country will not do this."

Russian Foreign Minister Sergei Lavrov also urged North Korea to be cautious, calling on the US to engage in one-on-one negotiations with North Korea to resolve international concerns over Pyongyang's nuclear programme.

Together with other countries involved in six-party talks with North Korea, "we are working with Pyongyang in order that it exercises restraint and in order to prevent hasty steps" by North Korea, Lavrov told journalists.

But the Russian minister cast doubt on Pyongyang's seriousness, saying: "It is not the first time that we've heard this kind of announcement, but for the most part these announcements have not been confirmed."

The current standoff over North Korea's nuclear programme erupted in 2002 when the United States accused Pyongyang of running a secret uranium enrichment programme in violation of a 1994 denuclearisation agreement.

But tensions between the US administration of President George W. Bush and Pyongyang have risen since North Korea test-launched seven missiles in July, heightening speculation that a nuclear weapons test was in the works.

The South Korean presidential Blue House had no immediate comment, as Tuesday is a public holiday marking National Foundation Day.

The Seoul government has for years adopted a "sunshine policy" of engagement with the North, but suspended regular aid shipments after the missile tests.

And a British expert on Japan and northeast Asia security, John Swenson-Wright, warned Tuesday's threat should not be underestimated, but said it could be part of a delicate diplomatic game of brinkmanship.

"It's very serious because of the implications for the region and for the Bush administration proliferation policy," the expert with the Chatham House international affairs think-tank in London told AFP.

"I would be surprised if they went ahead and tested. It exposes them to a great deal of risk, far more than the missile launch.