Authorities must be prepared for more foreign fighters to seek to return to Australia as advances are made against the Islamic State group in Iraq, Foreign Minister Julie Bishop said on Thursday.
Following talks with new US Secretary of State Rex Tillerson in Washington, Ms Bishop said gains made by coalition forces in the fight to retake the IS stronghold of Mosul could see more Australians in the region attempt to return home.
"That is likely to be the consequence of military success in Iraq, for the example the retaking of Mosul," Ms Bishop told ABC radio.
"That will mean that a number of foreign terrorist fighters will seek to flee from Iraq and the expectation is a number will seek to return home.
"We need to be prepared for that."
Ms Bishop said broad discussions with her new American counterpart had included the ongoing 30-day review of the fight against IS by the new Trump administration, and regional security issues in South-East Asia. A day earlier she met with Vice President Mike Pence for the first time.
Australian forces are involved in the latest large-scale operation to retake Mosul, where coalition forces have come under fire from militants as they move closer to front lines. A number of United States troops have been injured in recent weeks.
As many as 100 Australians are believed to have joined groups fighting in the Middle East.
Australia has declared the Mosul district as an area where listed terrorist organisations are engaging in hostile activities, making it a criminal offence for a person to intentionally enter or remain unless for a legitimate purpose.
Ms Bishop said coalition partner governments were optimistic land in the Mosul area would be reclaimed as a result of the fighting.
The deputy Liberal leader said there was "enormous goodwill" between the two governments but no request had been made for more Australian troops to join ongoing military operations in the Middle East, but any future request would be considered carefully by the Turnbull government.
"We're talking in terms of Australia's contribution over many years, so we have a particular perspective and insight that we wanted to share with the new administration."
Ms Bishop confirmed the government has invited Secretary Tillerson, the former boss of international oil giant Exxon Mobil, to visit Australia this year for annual bilateral talks.
