"Now is a time for calmness."

These words come from Foreign Minister Gerry Brownlee this afternoon amid news Australia will join with the United States if there is a North Korean missile strike.

Malcolm Turnbull said earlier Australia would enact the ANZUS Treaty and "come to the aid of the United States" if North Korea launched an attack against the western superpower.

READ MORE - Malcolm Turnbull "We'll help US"

But Foreign Minister Gerry Brownlee says the Australians have a formal alliance with the United States, which puts PM Malcolm Turnbull's stance on a different level.

Mr Brownlee says from our perspective we'd need to know the nature of the conflict. But he has reiterated the fact now is a time for calmness.

It has been a day of escalating threats between America and North Korea, who earlier this week threatened to launch a multi-missile strike in the waters off the US Pacific territory of Guam.

"The United States has no stronger ally than Australia. 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," Turnbull told 3AW radio.

"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 was an attack on Australia, the United States would come to our aid.

"You remember on 9/11 when the United States was attacked, John Howard invoked the ANZUS Treaty, Australia came to the aid of the United States. We stand together as we have done for generations."