Tony Abbott has again ruled out sending combat troops into Iraq, saying there has been no request for Australia to get more heavily involved in the conflict.
The prime minister on Sunday announced Australia will help deliver military equipment to Kurdish forces fighting Islamic State extremists in Iraq's north.
But Mr Abbott has dismissed speculation that could lead to a ground troop deployment.
"What President Obama has said all along - and what I say likewise - is that we are ruling out combat troops on the ground," he told the Nine Network on Monday.
Australia would continue to talk to its allies about military involvement "down the track".
"There has been no formal request and no decision taken to get further involved in actual military conflict," Mr Abbott said.
The prime minister dismissed complaints from the Greens and independents that parliament was not consulted about Australia's involvement in arming the Kurdish regional government.
He says military action is a matter for the executive government, not the parliament.
Mr Abbott defended the decision to boost Australia's involvement in the conflict beyond humanitarian airdrops.
The situation in Iraq was a humanitarian catastrophe and security nightmare, which posed a direct threat to Australia, he said.
"While it seems a long, long way away, it is reaching out to us," he said.
However, Australia would not follow the UK by increasing its terror threat level because of home-grown extremists.
"Obviously, we are constantly monitoring it," he said.
Mr Abbott said the weapons airlifts would begin in "coming days".
Fairfax newspapers are reporting SAS soldiers will provide protection to air crews during the operation, which will involve Australian planes landing in Kurdish territory.
But Defence Minister David Johnston disputed the SAS claim.
"To the best of my knowledge that's not happening," he told ABC radio.
"And we won't discuss what special forces are doing, were they to be involved in the future."
Senator Johnston conceded the mission would be dangerous and said every effort would be made to protect Australian personnel.
Independent MP Andrew Wilkie said it was "insane" that the power to approve military action rested with the prime minister and his senior ministers.
"It should be debated in the parliament and the evidence presented, hard evidence presented, so people can make a considered decision," Mr Wilkie told ABC radio.
"If the case is as compelling as the government claims ... then the parliament may well authorise the action."
Fellow independent Nick Xenophon backed the push for a parliamentary debate on Iraq, despite supporting the airlift.
"I think it's important that if we follow the US, we follow them after looking at all the facts," he said.
However, Family First Senator Bob Day rejected talk of parliament being involved in the Iraq deployment.
"I've got absolutely no reason to doubt that the government is handling this at the moment," he said.
But Greens deputy leader Adam Bandt also called for a full parliamentary debate on military involvement in Iraq.
"It seems when the United States says `jump', Tony Abbott and Labor say `how high?'" he told reporters in Canberra.
"Where is the case that (military intervention) will somehow make Australia safer?"
Mr Bandt said that horrific events were happening all over the world, but Australia did not intervene militarily in all of them.
He said the case had to be made for why military force was the only option.
"We have a very poor record picking sides in that part of the world and we're about to do it again," he said.
Labor frontbencher Tony Burke said so far there was bipartisan support for the government's decisions.
"I think it's quite clear what we're dealing with is quite different to what was dealt with a decade ago," he said.
There were opportunities to raise issues during parliamentary proceedings, so a specific Iraq debate was not necessary, he said.