Former Australian Prime Minister Kevin Rudd has accused Malcolm Turnbull of acting irresponsibly by pledging Australia's support for the U.S. if North Korea attacks America.
But one of Australia's defence ministers says Turnbull was only explaining how the ANZUS treaty works and any decision to commit troops was one for Cabinet.
"The United States has no stronger ally than Australia".
"If there is an attack on the United States by North Korea then the ANZUS treaty will be invoked and Australia will come to the aid of the United States, just as if there were an attack on Australia, the United States would come to our aid".
"We have an ANZUS agreement and if there is an attack on Australia or the United States then each of us will come to the other's aid", Mr Turnbull told 3AW radio on Friday.
Mr Rudd says it's a hard and risky time amid rising tensions over a potential North Korea strike, which call for "calm language" and "solid diplomacy" from leaders.
Crossbench senator Nick Xenophon said the ANZUS treaty was not about giving the United States a blank cheque.
"We can't sleepwalk our way into a conflict", Xenophon said.
Meanwhile, citing the Australia response to the September 11 terrorist attacks on the United States, Julie Bishop has told Sky News that if a threat were imminent, the Prime Minister would need to act quickly and enact the ANZUS treaty.
"It's not the parliament's role to make that decision", he said.
Asked about Tony Abbott's call for Australia to urgently consider a missile defence system, Mr Turnbull said the country is constantly reviewing its position.
"It would be tens of billions of dollars and take many years to replicate what the United States has done for continental U.S", Pyne told RN Breakfast.
"But of course if North Korea decides to carry out some of its violent threats then obviously bad consequences will follow, there's no point ducking that inevitable effect".
China, because of this view, will only do a few things to try and talk North Korea into coming around to a more reasonable posture.
"Kevin Rudd, I think, should recognise this is a serious matter and not one for political point scoring".
"At the end of the day if the North Koreans evolve into a fully replete nuclear weapons state with ICBMs (intercontinental ballistic missiles) with miniaturised warheads on top then, well, the Chinese view is, the U.S. will then just have to accept that reality", Mr Rudd said.
"His view and the view of his administration is that the way to resolve the situation with North Korea, as Donald Trump reaffirmed this morning in fact, is through these economic sanctions".