As the US launched tomahawk missiles at Syria in response to a chemical attack which claimed 72 lives, Australian Defence Minister Marise Payne said the Turnbull government would consider whether or not to join the ally in action against Syrian President Bashar al-Assad.

Roughly 60 cruise missiles were fired from two warships in the Mediterranean Sea, targeting a government-controlled air base in Syria 8-9pm (US East Coast Standard Time) - well into the darkness of Syria, according to news.com.au.

It came after US Vice-President Mike Pence upped criticism of the Assad regime in the wake of this week's deadly gas attack in northern Syria, telling US media "all options are on the table".

Asked if Australia would join any US action without UN backing, Defence Minister Marise Payne told ABC radio this morning: "We'll make decisions in regard to those sorts of issues as they are brought to us."

Advertisement

Senator Payne said the most important thing now is to condemn the attack.

"We have to be clear with Russia, we have to be clear with those who support the regime that this is totally unacceptable," she said.

The minister said Australia would "of course" be part of the conversation about possible US action.

Prime Minister Malcolm Turnbull wouldn't go into detail about the matter during his regular spot on radio 3AW Melbourne this morning, but said "we have been in close touch with our American allies".

He noted Australia is already involved in coalition air strikes against Islamic State in Syria.

"It is horrifying we condemn it utterly. This is a war crime of the worst sort, its inhuman, and it has been universally condemned," he said.

He added: "It cries out for a strong response."

Turnbull said "there doesn't appear to be any doubt" that Syrian government forces were behind the gas attack.

He said the role of Russia has yet to be determined but the country "is the principal foreign sponsor of the Assad regime."