SEOUL (Reuters) – North Korea, defiant in the face of international condemnation of its latest nuclear test, fired two more short-range missiles off its east coast yesterday and accused the United States of plotting against its government.

In a move certain to compound tensions in the region, South Korea said it would join a US-led initiative to intercept ships suspected of carrying weapons of mass destruction, something Pyongyang has warned it would consider a declaration of war.

South Korea’s Yonhap news agency quoted a government source in Seoul as saying the North had test-fired one surface-to-air and one surface-to-ship missile off its east coast. The missiles had a range of about 130 km (80 miles).

North Korea could also launch by today more short-range missiles, perhaps toward a disputed sea border with the South, South Korean media quoted government sources as saying.
North Korea fired off three short-range missiles on Monday.

The nuclear test on Monday, the North’s second after one in 2006, drew sharp rebuke from regional powers, and US President Barack Obama called Pyongyang’s nuclear arms programme a threat to international security.

The demonstrations of military might have also taken a toll on Seoul’s jittery financial markets, worried about the impact of North Korea’s growing belligerence in a region which accounts for a sixth of the global economy.

Underlining concerns over how far the North might be prepared to raise the stakes, Obama assured South Korean President Lee Myung-bak of Washington’s unequivocal commitment to defense on the long-divided peninsula, where some two million troops face off.

There is little more Washington can do to deter the ostracized North, punished for years by international sanctions and so poor it relies on aid to feed its 23 million people.

Brushing aside international condemnation, Pyongyang said the United States was the aggressive one, its usual argument to justify having a nuclear arsenal. “Our army and people are fully ready for battle … against any reckless US attempt for a pre-emptive attack,” the North’s KCNA news agency said.

Analysts say Pyongyang’s military grandstanding was partly aimed at further tightening leader Kim Jong-il’s grip on power so he can better engineer his succession. Many speculate he wants his third son to take over.

The nuclear test was also bound to raise concerns about proliferation. The United States has in the past accused Pyongyang of trying try to sell its nuclear know-how to other states including Syria. Some analysts say it also has close military ties with Iran.

“The DPRK’s nuclear test not only poses a serious threat to peace and stability on the Korean peninsula, and southeast Asia and beyond, but also represents a grave challenge to the international non-proliferation regime,” South Korean disarmament ambassador Im Han-tauck told the UN-sponsored Conference on Disarmament in Geneva.

A North Korean diplomat told the 65-nation Geneva conference that denunciations of its nuclear test could prevent it from supporting the group’s moves to curb production of nuclear bomb-making material, jeopardizing the start of global talks on the  issue.

An Myung Hun said Monday’s underground explosion was a “self-defense measure.”
The UN Security Council condemned the nuclear test and is working on a new resolution.
Interfax news agency in Moscow quoted a Russian Foreign Ministry source as saying the adoption of a tough resolution was probably unavoidable because the Security Council’s authority was at stake.