The United States has right to launch a pre-emptive military strike against North Korea if there was "solid evidence" that Pyongyang planned to attack the US or South Korea, an influential lawmaker said today.

"If we have good reason to believe there's going to be an attack, I believe we have the right to take pre-emptive action," Peter King, the Republican Congressman from New York, told the CNN.

"I don't think we have to wait until Americans are killed or wounded or injured in any way," King said.

"I'm not saying we should be rushing into war, don't get me wrong, but if we have solid
evidence that North Korea's going to take action, then I think we have a moral obligation and an absolute right to defend ourselves," he said.

North Korea has warned that US bases in Hawaii and Guam would be targeted in what could turn into "an all-out war, a nuclear war". The communist regime has already declared a "state of war" with South Korea.

According to a latest Gallup poll, if North Korea were to attack South Korea, the majority of Americans (55 per cent) say the US should use its military forces to help defend the South, while 34 per cent say the US should not do so.

Relatively few Americans - 28 per cent - think it is likely that North Korea will attack the US in the next six months.

It is not clear whether North Korea is capable of hitting the US mainland with missiles, but there is an increasing focus on the possibility of attacks on US military forces stationed in the Pacific.

As a result, the US is rapidly moving a missile defense system to the US possession of Guam in the Pacific Ocean, Gallup said.