American officials have reportedly suggested Australian warplanes could be involved in a new international military effort in Iraq and Syria.

Australian warplanes could be involved in new international military action in Syria and Iraq, US officials have reportedly said.

The New York Times has reported Obama administration officials saying the US president is close to a decision on authorising further airstrikes, particularly against Islamic State forces laying siege to the northern Iraqi town of Amerli.

Barack Obama said in a speech earlier this week the US was building a coalition to take the fight to the “barbaric terrorists”.

The officials said they expected that Britain and Australia would be willing to join the United States in an air campaign.

Experts suggest any air campaign would likely involve RAAF Super Hornets either escorting other aircraft or attacking ground targets.

A Defence Department spokesman told AAP on Wednesday that Australia was not currently participating in Iraq air strikes, but would do what it could to prevent a humanitarian disaster.

“The government is continuing to consult with our friends and partners including the government of Iraq, about what help might be given,” the spokesman said.

“However, no decision has been made so far committing Australian forces to join air strikes targeting ISIL forces either in Iraq or Syria.”

Mr Obama met with the secretaries of state and defence overnight, but a White House spokesman said he had yet to authorise further military force.

The White House spokesman told reporters the situation in Iraq and Syria would require the involvement of Western allies.

Prime Minister Tony Abbott told reporters on Tuesday that Australia stood ready to provide more humanitarian support and was continuing to talk about what could be done to provide “peace and safety” in northern Iraq.

The US has begun surveillance flights over Syria to collect information on possible Islamic State targets for airstrikes, potentially in the eastern province of Deir Ezzor.

Kurdish forces fighting Islamic State in northern Iraq have been pledged weapons and ammunition from Albania, Canada, Croatia, Denmark, France, Italy and Britain.

The Kurds have also lobbied Australia for support.

Foreign Minister Julie Bishop said she was made aware of a letter from the Kurdish representative in Canberra on Wednesday and it was being considered by the national security committee of cabinet.

Debate is simmering in Australia and the US on the legal basis for any stepped-up military action in Iraq and Syria.

Some senior US Republican and Democratic party have called for a vote in Congress to endorse further action, which is currently being undertaken under the authority of the President as Commander-in-Chief.

Labor does not support Australian combat troop deployment, but backs the humanitarian mission.

The Australian Greens have urged the government to put any defence force involvement to a vote in parliament.

Foreign Minister Julie Bishop said Australia’s next role would depend on what the Iraqi government wanted it to do.

“Anything further would need considerable discussion,” she told Sky News, adding Australia stood ready to provide further humanitarian assistance.

Australian Greens leader Christine Milne said parliament must be allowed to debate any move to deploy Australian forces to Iraq.

“After what John Howard got us into in Iraq in the first place, it would be appalling if Prime Minister Abbott just goes along with the US and UK again,” she told reporters.

The Greens will support humanitarian assistance but not military engagement.