SYDNEY - Australia's prime minister told an Asia-Pacific regional conference on Thursday that terrorism was a modern form of treason and the region's greatest security challenge.

Prime Minister Tony Abbott gave an opening address to delegates from about 30 countries attending a conference in Sydney on countering terrorism propaganda and enhancing regional cooperation.

The work of the conference was to share experiences "so that all of us can learn to be more effective in grappling with the biggest security challenge of our time," Abbott said.

He said Australia was "looking at what can be done to deal with Australian citizens who have betrayed our country by fighting with terrorists, this modern form of treason."

The government plans to introduce laws that would allow dual nationals to be stripped of their Australian citizenship if they were suspected terrorists. Government ministers are divided over whether Australians who are not dual nationals should also lose their citizenship.

"In the end, though, the only really effective defense against terrorism is persuading people that it's pointless," Abbott said.

"Above all, we need idealistic young people to appreciate that joining this death cult is an utterly misguided and wrong-headed way to express their desire to sacrifice," Abbott said, referring to the Islamic State group.