North Korea says useless to talk to hostile U.S.

North Korea rebuffed the latest overtures from the Obama administration by saying on Friday it was useless to talk to the United States whose "hostile policy" left it no choice but to bolster its nuclear deterrent.

Stephen Bosworth, the U.S. point man for North Korea policy, began a swing through Asia on Thursday to discuss how to rein in the prickly North after it raised regional security concerns by threatening last week to test a nuclear device.

""The study of the policy pursued by the Obama administration for the past 100 days since its emergence made it clear that the U.S. hostile policy toward the DPRK (North Korea) remains unchanged," the official KCNA news agency quoted an unnamed Foreign Ministry spokesman as saying.

"There is nothing to be gained by sitting down together with a party that continues to view us with hostility."

He added: "The DPRK will bolster its nuclear deterrent as it has already clarified."

U.S. President Barack Obama team's said it was willing to consider direct talks with reclusive North but wanted to persuade Pyongyang to return to stalled disarmament-for-aid talks among the two Koreas, China, Japan, Russia and the United States.

Last month, North Korea said it was quitting the six-way talks and would restart a plant that separates plutonium from spent nuclear fuel rods in response to being punished by the United Nations for the April 5 launch of a long-range rocket.

North Korea insists it sent a satellite into orbit and had the right to do so as a part of a peaceful space programme.

U.S. and South Korean officials said nothing was put into orbit and the launch was a disguised test of a long-range missile that violated U.N. resolutions.

Destitute North Korea, which conducted its only nuclear test in October 2006, later said it had resumed producing arms-grade plutonium at its Soviet-era Yongbyon nuclear plant.

It then threatened a fresh nuclear test and ballistic missile test launch unless the U.N. Security Council apologised for chastising the state and tightening existing sanctions that limit its overseas arm trade, a key source of hard currency.

A South Korean news report said on Thursday there was increased activity at North Korea's known nuclear test site, suggesting Pyongyang was gearing up for a new test.

Bosworth was due to arrive in Seoul later on Friday from Beijing. He will go to Tokyo and Moscow next week.