Australia has warned the Russian ambassador has country must not block an investigation into Syria's use of chemical weapons.
Russia used its veto power at the United Nations Security Council on Wednesday to prevent an investigation into the attack by Bashar al-Assad's regime on Douma.
Up to 80 people were killed and hundreds more injured in the attack on the beseiged town in eastern Ghouta.
Foreign Minister Julie Bishop said Russian ambassador Grigory Logvinov was given the stark warning on Tuesday, after threats his country would use its veto power.
"We urge Russia not to stand in the way into an investigation into the use of chemical weapons in Syria," she said.
"We have advised the Russian ambassador in Canberra yesterday that we expect Russia to fulfil its responsibilities as a permanent member of the United Nations Security Council to not shield the Syrian regime from an investigation into the use of chemical weapons which has killed a number of civilians."
US President Donald Trump threatened that "everybody's gonna pay a price" for the attack.
Ms Bishop said Australia would support US action that was "targeted, calibrated and proportionate".
The US carried out air strikes last year after the Syrian regime used a sarin nerve agent in an attack at Khan Sheikhoun that killed 90 people.
Russia also vetoed an investigation into that attack.
One US official said the US, France and Britain were considering more extensive military options than the punitive, one-day strike last April.
Labor's foreign affairs spokeswoman Penny Wong said if Russia had no involvement in the attack it should welcome an investigation.
"If Russia and other parties, including the (Syrian) regime believe that they were not involved in this attack then they have nothing to fear from the independent investigation the United Nations is seeking," she told ABC radio.
The Organisation for the Prohibition of Chemical Weapons will send a fact-finding mission to Douma, after receiving a request from the Syrian government and its Russian backers to investigate the allegations.
The Russian military, which has troops in Syria, said on Monday its officers had visited the site of the alleged attack and found no evidence to back up reports of poison gas being used.