The prime minister met with the Chief of the Defence Force, Air Chief Marshall Mark Binskin, at the Australian Signals Directorate building in Canberra.
He was joined by defence minister Marise Payne.
Mr Turnbull said Australia stood “shoulder to shoulder” with the United States on the North Korean crisis, reaffirming his promise to join any conflict with the rogue state.
It comes as North Korean leader Kim Jong-un is threatening to fire four missiles into the sea near the United States territory of Guam, in the Pacific Ocean.
Rhetoric has escalated on both sides, with US President Donald Trump threatening swift retaliation.
“North Korea best not make any more threats to the United States,” Mr Trump said.
“They will be met with fire, fury and frankly power the likes of which this world has never seen before.”
Mr Turnbull spoke with the US vice president, Mike Pence, overnight, and reaffirmed where Australia stands. He indicated that the US wishes to find a resolution through economic sanctions.
“The ANZUS Treaty means that if America is attacked, we will come to their aid. If Australia is attacked, America will come to our aid. We are joined at the hip. The American alliance is the bedrock of our national security,” Mr Turnbull said.
He repeated calls for North Korea to “come to its senses” and praised a recent tightening of UN economic sanctions, which were agreed to by China and Russia.
Opposition leader Bill Shorten says while "the politics of Labor and Liberal are working absolute together", de-escalation is important.
"The big concern is actually not the United States, it's the bellicose and provocative actions of the North Korean dictatorship," he told reporters.
"I think there is an important role for china to play here and of course we rely upon leadership from the United States."
However, Greens leader Richard Di Natale labelled Mr Trump "unhinged and paranoid", criticising Mr Turnbull's declaration of Australia's strong US alliance.
"Malcolm Turnbull, by backing in Donald Trump, has just put a target on our back," he told reporters.
-With AAP
