Australia's role in the fight against so-called Islamic State in the Middle East could last "years", Foreign Minster Julie Bishop has said.
The remarks came after the Australian government said its aircraft would participate in missions against IS in Syria.
Previously its jets were only flying missions against the militant group in Iraq as part of the US-led coalition.
Australia has also sent soldiers to help train and advise Iraq's army.
Ms Bishop told local media Australia was committed to destroying the militant group.
"We've always spoken about our involvement in Iraq in terms of years, not months or days," she said.
Defence Minister Kevin Andrews told ABC the country's role in the Middle East conflict would last "two or three years, I can't say in exact terms".
The Australian air force has been bombing IS targets in Iraq for about 12 months, but the US last month asked Australia to help pursue targets in Syria.
This week Australia announced it would take in an additional 12,000 migrants who are fleeing the Syrian crisis, on top of the 13,750 overall intake of confirmed refugees for 2015.
Australia will also give A$44m ($32m; £21m) to the UN to directly pay for the support of 240,000 displaced people in countries neighbouring Syria and Iraq.
That would increase Australia's total humanitarian aid to the Syria and Iraq conflicts to A$230m since 2011.
Europe is struggling to cope with its worst migrant crisis since World War Two, with tens of thousands crossing European borders.