Australia will come to America's aid if North Korea launches an attack against the US, Malcolm Turnbull has confirmed.
The prime minister discussed the unfolding situation with US Vice President Mike Pence on Thursday night and received a briefing from the Chief of the Defence Force Mark Binskin and security officials in Canberra on Friday.
Mr Turnbull said the stability of the world was being put at risk by North Korea, and he was committed to working with the US to resolve the situation through diplomatic and economics means.
"But we stand shoulder to shoulder with the United States," Mr Turnbull said outside the briefing with Air Chief Marshal Binskin.
"The ANZUS treaty means that if America is attacked, we will come to their aid and if Australia is attacked, the Americans will come to ours. We are joined at the hip. The American alliance is the bedrock of our national security."
Asked earlier on radio about Tony Abbott's call for Australia to urgently consider a missile defence system, Mr Turnbull said the country is constantly reviewing its position.
He said the advice from Defence is there is a no benefit to deploying a US-style 'Terminal High Altitude Area Defence' (THAD) system.
"The reason for that is that THAD's designed to provide protection for relatively small areas against short-to-intermediate range missiles," he said.
The US sees the way to resolve the situation as being through economic sanctions, despite Donald Trump's threats of "fire and fury", Mr Turnbull said.
"That is the preferred way to deal with it but of course if North Korea decides to carry out some of its violent threats then obviously terrible consequences will follow," he said.
Defence Minister Marise Payne and Vice Chief of the Defence Force Ray Griggs also attended the Canberra briefing.
Labor leader Bill Shorten believes nations need to concentrate on encouraging Pyongyang to de-escalate tensions.
"The big concern is actually not the United States, it's the bellicose and provocative actions of the North Korean dictatorship," he told reporters in Canberra.
Mr Shorten insists the government and opposition share the same concerns about North Korean leader Kim Jong-un's pursuit of nuclear missiles.
"Australians should be reassured that on this matter of North Korea and our national security, the politics of Labor and Liberal are working absolutely together," he said.
Australian National University's Professor Hugh White said the words of national leaders such as Mr Turnbull could influence Mr Trump's future actions.
"There is a lot of uncertainty about what America has got in mind, and therefore I think it was a bit unwise of Mr Turnbull to commit Australia so plainly," Prof White said.
Greens leader Richard Di Natale said Mr Trump was "unhinged and paranoid" and Australia should distance itself from the US alliance.
"Malcolm Turnbull, by backing in Donald Trump, has just put a target on our back," Senator Di Natale said.
