US Under Secretary of State John Bolton

"This is not at all unexpected. The North Koreans were not adhering to the treaty when they were still a part of it.

"Their conduct and their rhetoric don't square."

Chinese Foreign Ministry statement

"We feel concerned... The treaty is of important significance to prevent the proliferation of nuclear weapons and enhancing international peace and security.

"We hope to continue to maintain the universality of this treaty and will continue to work to promote a peaceful resolution of the North Korean nuclear issue."

Japanese Prime Minister Junichiro Koizumi

"We are deeply concerned. We see this is a very serious matter.

"Our country through co-operation with the United States, South Korea and other countries concerned - as well as the International Atomic Energy Agency - will demand that North Korea goes back on its decision."

Russian Foreign Ministry statement

"This move can only aggravate the already tense situation in the Korean peninsula and seriously weaken international treaties ensuring regional security.

"Russia hopes that Pyongyang will take account of the unanimous opinion of the world community, and of its neighbours and partners, and opt to respect its international obligations with respect to non-proliferation."

South Korean President Kim Dae-Jung

"The North's withdrawal from the Non-Proliferation Treaty brought the situation on the Korean peninsula from bad to worse by one step.

"But at the same time, thanks to our efforts, the United States is now moving toward dialogue with North Korea. We have to make the Korean peninsula free of nuclear weapons.

"For this purpose, we have to be patient and persistent in achieving a peaceful solution."

French Foreign Minister Dominique de Villepin

"France condemns this decision which underlines the need for continuing the bilateral, regional and multilateral efforts [to solve the crisis].

"It is a serious decision heavy with consequences, that has to be dealt with by the United Nations Security Council. This major development underscores the necessity and the urgency of international mobilisation."

Australian Foreign Minister Alexander Downer

"Obviously all of these developments... are a matter of great concern throughout the Asia-Pacific region and indeed beyond.

"I think Australia can play a useful role in at least helping to put in place the path for a diplomatic solution, but I wouldn't want to overstate what impact the Australian officials will be able to have."