Aussie 'extremists' pose concern

Julie Bishop has raised fears that Australians are working with extremist groups linked to the war erupting in Iraq and then returning home.

The Foreign Affairs Minister also believed there was little chance Australia would send troops into Iraq to deal with the outbreak of violence in the country's north.

Prime Minister Tony Abbott held talks with US President Barack Obama last week, with much focus on the way the Islamic State of Iraq and Syria have swept across northern Iraq in recent days.

Ms Bishop said part of the broader problem had been foreign nationals, including Australians, going to Syria where they were being exposed to extremists like ISIS.

The PM has not ruled out Australian military involvement in Iraq, but Ms Bishop said she did not "envisage a circumstance where we would be sending in troops".

"But we certainly stand ready to support the humanitarian crisis," she said.