Australia, a close ally of the United States, is due to take over the rotating leadership of the council on Sunday, a role that requires it to assist council members to reach agreement.
"We're moving to a stage where America and like-minded countries are contemplating what sort of response," Carr told reporters on Wednesday.
"Our preference, everyone's preference, would be for action, a response, under United Nations auspices. But if that's not possible, the sheer horror of a government using chemical weapons against its people, using chemical weapons in any circumstances, mandates a response."
The United States and its allies are gearing up for a probable military strike against Syria that could come within days and would be the most aggressive action by Western powers in Syria's two-and-a-half-year civil war.
"Russia and China can't be vilified in this. They need to be engaged with, encouraged to look at the evidence, and encouraged to think about their attitudes towards the Assad regime and what the world does when a population is being devastated, and now devastated with the application of weapons that terrifyingly enable mass atrocity crimes," he said.
The crisis in Syria, Carr said, had re-exposed a flaw in international governance, with the right of permanent U.N. Security Council members to veto any decision.
(Editing by Mark Bendeich)