If North Korea hits Guam then it's game on: US defence chief

United States Defence Secretary James Mattis on Monday said that the U.S. military would know "within moments" if the North Korean missile launched is heading towards the U.S. territory or not, including Guam.

He issued a strong warning to North Korea saying, "If they shoot at the United States, I'm assuming they've hit the United States. ... If they do that, then it's game on."

"US military would be able to determine 'within moments' after launch whether or not a North Korean missile was headed for US territory, including Guam. He later added that the US would 'take it out' if the missile was determined to be headed for any US territory," CNN quoted Mattis, as saying.

However, he clarified that a declaration of war remains with President Donald Trump and Congress.

"War is up to the President, perhaps up to the Congress, the bottom line is we will defend the country from an attack, for us that's war, that's a wartime situation," he said.

"We will defend the country from any attack, at any time, from any quarter. Yes, that means for a lot of young troops they're going to be in a wartime situation, welcome to reality. But it's not declaring war, it's not that I'm over here Dr. Strangelove doing things like that," he added.

Soon after Mattis's warning, North Korean leader Kim Jong Un, reportedly, reviewed his military's plan to launch missiles at Guam.

Tensions between North Korea and the U.S. have escalated after two ICBMs were tested by Kim Jong. President Trump has pledged to meet further provocations "with fire and fury like the world has never seen".

North Korea further threatened to attack Guam and other US territories in the Pacific region, with a government spokesman saying a strike plan was ready "to put into practise in a multi-current and consecutive way any moment" on Kim's instruction.