Cabinet is expected to give formal approval for the RAAF to conduct air strikes in war-torn Syria.
The announcement will be made on Tuesday, radio station 2GB reported.
Prime Minister Tony Abbott previously said a final decision on the US government’s formal request for air support would be made this week.
If true, the announcement would coincide with a similar decision by France.
On Tuesday (AEST), French president Francois Hollande said his country would take action to allow it to “plan” air attacks in Syria.
“I have asked the defence ministry that from tomorrow surveillance flights can be launched over Syria, allowing us to plan air strikes against Daesh [the Islamic State group],” Mr Hollande told a press conference in Paris.
He said that finding a political transition that sidelined Syrian President Bashar al-Assad was “essential”.
“The transition is an essential point. Nothing must be done that can consolidate or maintain Bashar al-Assad.”
The Islamic State terror group has reportedly seized the last major oilfield under Syrian government control, a group monitoring the conflict claimed on Monday.
“The regime has lost the last oilfield in Syria,” the Britain-based Syrian Observatory for Human Rights said in a statement.
It did not mention when the Jazal field allegedly fell to the extremists.
Commentators on social media said the medium-sized oilfield, located to the north-west of the rebel-held ancient city of Palmyra, might have been taken on Sunday.
The Observatory said US-led coalition bombing raids in areas in the militant’s de facto capital of Raqqa had killed at least 16 militants, including five foreign jihadists.
-with ABC and agencies.