Regime that 'uses chemical weapons against its own people has to be made to pay a price', foreign minister says

Bob Carr says Australian troops won't take part in an intervention in Syria

Australian troops won't be sent to Syria in the event of a military intervention by western forces, the foreign minister, Bob Carr, says.

The US and France say they're ready to step in, responding to the apparent chemical attack on civilians outside Damascus last week, but Russia has warned against such a move.

The Syrian president, Bashar al-Assad, has denied responsibility for the attack, which is believed to have killed as many as 1300 people.

The prime minister, Kevin Rudd, says there's overwhelming evidence chemical weapons were used. And Carr is convinced Assad forces were behind the attack.

"A government that uses chemical weapons against its own people has to be made to pay a price," Carr told a business conference in Perth on Wednesday.

"The evidence accumulates that this chemical weapons attack did take place and came from the Assad forces."

Carr said the preference would be for a UN-sanctioned action, but if that was not possible, "the sheer horror" of the attack mandated a response. He said Russia could not be vilified for its position.

Australia will take up presidency of the UN security council on 1 September and has to engage with Russia on the issue, along with China, he says.

He said the crisis had exposed a flaw in international governance, with any one of the security council's five permanent members able to veto a decision.

Asked if he was worried about retaliation by Syria to any intervention, Carr said: "You have to be. An attack on Syria is an act of war."

But the US was weighing those risks carefully, he said. He ruled out Australian troops playing a role.