Seoul (AsiaNews) – If the US continues to put pressure on North Korea for its nuclear programme, "we will regard it as a declaration of war and will take a series of physical corresponding measures," the North's Foreign Ministry said in a statement carried by the country's papers in response to statements made in Washington, Seoul, Tokyo and Beijing following North Korea's underground nuclear test on Monday.

The governments most closely involved in the crisis are currently discussing at the United Nations ways to impose sanctions on North Korea as 'punishment' for its nuclear test.

Tokyo and Washington want to take a hard-line and demand any decision include the use of force as a 'deterrent'. They have already unilaterally imposed sanctions banning North Korean ships and goods from entering their respective territories and maritime waters. They have also put an end to humanitarian aid.

Beijing has agreed to a ban on goods and a maritime embargo, but warns that any reference to the use of force would raise tensions in the region. Moscow, for its part, said that diplomacy is the safest path to follow till further developments.

South Korea's position is more complex. For years Seoul has pursued a policy designed to entice the North to cooperate, but must now deal with a population that will no longer allow the government to provide humanitarian and economic aid to those who would destroy them.

According to Shin Ki-nam, from the governing Uri Party and chairman of the National Assembly's Intelligence Committee, "the popular reaction is understandable" but that does not mean that our "policy is a failure".

Shin explained that the "nuclear test changed undoubtedly bilateral ties with the North but that does not mean that our policy is wrong. Of course, without a drastic change in attitude we won't be able to successfully pursue other common projects for quite some time."

In response to international reaction, Kim Yong Nam, who is second only to Kim Jong Il, said that how Pyongyang responded depended on how Washington responded. "The issue of future nuclear tests is linked to US policy toward our country" and to UN resolutions.