NIAGARA FALLS (Canada) - NORTH Korea's continued provocations are 'deeply regrettable,' top US diplomat Hillary Clinton said on Saturday, vowing to do 'all we can' to halt Pyongyang's nuclear proliferation.

Her comments came after the reclusive communist regime defiantly vowed to build more nuclear bombs and to start enriching uranium for a new atomic weapons programme following the UN Security Council's unanimous vote on Friday to impose tougher sanctions for Pyongyang's nuclear test.

What Resolution 1874 is about ALL 15 Security Council members endorsed the compromise resolution sponsored by Britain, France, Japan, South Korea and the United States. The text of Resolution 1874, which does not authorise the use of force, calls on UN member states to slap expanded sanctions on North Korea in response to its May 25 underground nuclear test and subsequent missile firings. ... more

'We intend to do all we can to prevent continued proliferation by the North Koreans,' Mrs Clinton told reporters at Niagara Falls on the Canadian side of the border with the United States.

'The North Koreans' continuing provocative actions are deeply regrettable.' The North Koreans, Mrs Clinton said, 'have now been denounced by everyone. They have become further isolated. And it is not in the interests of the people of North Korea for that kind of isolation to continue.' The North, describing the sanctions resolution as a 'vile product' of a US-inspired campaign, said it would never abandon nuclear weapons and would treat any attempt to blockade it as an act of war.

The international pressure, the North said, is aimed to 'disarm us and suffocate economically' in order to dismantle the ideology and system chosen by its people.

US ambassador to the United Nations Susan Rice warned on Friday that the tough new UN sanctions could prompt Pyongyang to react with 'further provocation.' The hardline communist state, in a foreign ministry statement reported by its official news agency, said all new plutonium it extracts would be weaponised.

One third of used fuel rods from the Yongbyon reactor have so far been reprocessed into weapons-grade plutonium, it said.

'Secondly, we will start uranium enrichment,' it said in its first admission that it has such a programme - a second route to a nuclear bomb.

In 2002, the North denied US claims that it was operating a secret uranium enrichment programme in addition to its admitted plutonium-based operation.

The plutonium-producing plants were shut down under a 2007 six-nation disarmament deal. But Pyongyang vowed to restart them after the Security Council in April condemned its long-range rocket launch. -- AFP