Security agencies will analyse a video featuring an Australian man who is reportedly a combat medic fighting with rebels in Syria, Foreign Minister Julie Bishop says.

Channel Seven has aired the footage of the man, who says his name is Abu Ousama and describes himself as a "true blue Aussie". The ABC has not independently verified the footage.

In the video, he defends the Islamic State (IS) militant group and questions how beheading people can be wrong.

"You have these beheadings. Some people might call them barbaric," he said.

"But what is the difference between a missile that hits into a house, which kills 15 kids compared to a man dying getting cut by his throat?"

The man, who appears in the video with a face covering, revealing just his eyes, says he is not afraid to die in the conflict.

"I hope that Allah accepts the good that we've done and blesses us with his reward ... of the highest of paradise," he said.

"What more could you want?"

However, he said there was no hatred between him and Australia and that he is disappointed Australian forces are carrying out strikes against IS in Iraq.

"Home is home, everybody is going to love their country," he said in the video.

"[But] I'm sad to see Australia taking that step to come into a place it doesn't need to be because it will cause a reaction, it will cause people to hate it."

Ms Bishop says such men pose a potential threat to national security and the video will come under closer scrutiny.

"We will take whatever steps we can to keep Australians safe but also prevent Australians from taking up with terrorist organisations and similar organisations so our intelligence, police, security will be looking at that video very closely," she said.

"It's unthinkable someone would think beheadings are part of a territorial aspiration.

"These are murderous cults and they are using Islam to cover up for their violent behaviour. They are using religion as an excuse for what is simply murder.

"We want Australia to be the tolerant, free, open society it always has been and the example of that video indicates why the Australian Government is taking such a tough stance against foreign fighters."

Speaking outside the Tasmanian Liberal Party Conference on Saturday, Ms Bishop indicated she would suspend the passports of people with links to terrorist organisations if she had the power to do so.

The Parliament is considering legislation that will allow passports to be suspended without notification as part of ongoing investigations.

"What we are seeking to do is change the laws so that not only will I have the power to cancel a passport, but also the power to suspend a passport in circumstances where our intelligence agencies are not quite able to meet the threshold required to cancel a passport but want to have enough time to provide the evidence that would give rise to a negative security assessment," she said.

"In this way we are seeking to stop people leaving the country to take up with terrorist organisations and to prevent them coming back into the country if they have been fighting with a terrorist organisation."

Ms Bishop said she has now cancelled 60 passports in a bid to stop younger Australians travelling to and from the conflict zones in Syria and Iraq.

Editor's note (October 13, 2014): An earlier version of this story suggested Channel 7 had not verified the footage. The story has now been amended to make it clear the ABC has not independently verified the footage which Channel 7 ran.