Phnom Penh: US Secretary of State Hillary Clinton says North Korea's pursuit of nuclear weapons and ballistic missiles and "pattern of provocations" are a serious threat to Asian and world security.

North Korea released a statement later today at the Association of Southeast Asian Nations' annual conference in Cambodia saying Washington's "never-ending nuclear threat" against the North has forced Pyongyang to build atomic weapons.

Animosity runs high after a North Korean rocket launch in April that Washington and Seoul call a cover for a banned long-range missile test. North Korea says it was a satellite launch attempt.

Clinton says Pyongyang's new leadership should focus on its people's "needs and aspirations" so it doesn't "fall further behind."

The North's statement says its nuclear program is a deterrent that reduces the risk of war.