Politicians in Australia and Turkey have voted to allow their forces join the US-led fight against the Islamic State.
The Australian Government has authorised its fighter jets to carry out air strikes on IS targets in Iraq.
Prime Minister Tony Abbott described the terrorist group as a "death cult" that had "declared war on the world", adding it must be stopped.
The Turkish parliament, meanwhile, has voted overwhelmingly in favour of using its military forces in Iraq and Syria.
The coalition of countries fighting the terrorist group has now grown to 40 nations, including France and Britain.
British Prime Minister David Cameron says he is confident the mission has so far been effective, after a week of RAF strikes on targets in Iraq.
Last Friday, the British parliament gave approval by 524 votes to 43 for Britain to join the US-led coalition in the Middle East after Mr Cameron said IS forces are "psychopathic terrorists trying to kill us".
The US Defence Secretary Chuck Hagel, meanwhile, held a progress meeting with his French counterpart at the Pentagon last night:
