Prime Minister Tony Abbott is heading home from New York for Cabinet talks which could see Australian forces joining the war against Islamic State (IS) terrorists in Iraq.

Mr Abbott will touch down in Canberra this morning.

His talks in the United States this week have satisfied one of the last criteria he said needed to be met before he would make a military commitment.

Now all that is left are security and Cabinet meetings and consultation with the Opposition, which could be done tomorrow or early next week.

Before leaving the US, Mr Abbott met FBI and New York Police Department Chiefs at the Joint Terrorism Taskforce Centre, one of the nerve centres fighting terrorism.

Mr Abbott toured the centre, viewing exhibits detailing its successes, including the capture and killing of Osama Bin Laden.

The Prime Minister praised the centre’s work.

“You’ve been helping us everywhere not just helping people in New York,” he said.

Australian planes ‘on standby’ to join in bombing raids against IS

Australian planes are on standby in the Middle East, awaiting the go ahead to join the international coalition in bombing raids against IS, help Iraq is grateful for.

“We in Iraq are determined to cleanse our land of ISIS,” the Iraqi president Mohammed Fuad Masum said, using a difference acronym for IS.

“We would like to stress to you that eliminating terrorism in Iraq will be an important step in the direction of protecting the world and ridding the world from this danger.”

Across the border in Syria, the US is warning airstrikes alone would not be enough to defeat the militants.

“There has to be a ground component to the campaign against ISIL in Syria and we believe that the path to develop that is the Syrian moderate opposition,” the US Joint Chiefs of Staff chairman Martin Dempsey said.

The US plans to train 5,000 Syrian rebels, but General Dempsey has flagged up to 15,000 could be needed.

“We have to do it right not fast,” he said.

“They have to have military leaders that bind them together.”