The Islamic State group has shown it is prepared to use chemical weapons and is likely to have among its recruits the technical expertise to develop them, Australia's Foreign Minister Julie Bishop said.
In a speech late Friday, Bishop said Australia had no doubt that the Syrian regime had used toxic chemicals including sarin and chlorine over the past four years.
But she said apart from some crude and small scale endeavours, the conventional wisdom had been that the Islamic State group's intention to acquire and weaponise chemical agents was largely aspirational.
"The use of chlorine by Daesh, and its recruitment of highly technically trained professionals, including from the West, have revealed far more serious efforts in chemical weapons development," she said in Perth, using the Arabic acronym for IS.
"Daesh is likely to have amongst its tens of thousands of recruits the technical expertise necessary to further refine precursor materials and build chemical weapons."
The use of chlorine in homemade bombs has been reported in several parts of Iraq and Syria, with car and roadside bombs easy to rig with chlorine canisters.
And in March, Iraq's autonomous Kurdistan government said that analysis of soil and clothing samples showed that IS used chlorine gas in a car bomb attack in January.
In a speech to the Australia Group, which works to deny licences for the export of chemical and biological-weapon related materials, Bishop said a global effort was needed to prevent the proliferation and use of the toxic chemicals.
Speaking of the use of chemical weapons in Syria, she said: "The fact that atrocities such as this continue to occur shows that we must remain vigilant to the threat of chemical and biological weapons."
"Export controls and their effective implementation are as important as ever as threats to global security, continue to evolve."
Bishop said the rise of global terror groups such as IS was one of the gravest security threats faced by the world.
Bishop has previously warned that the numbers of Australians seeking to go overseas to fight with IS was not declining, with more than 100 fighting alongside jihadist groups in Iraq and Syria.
Australia has introduced a series of national security measures over the past few months to combat the threat, including criminalising travel to terror hotspots.