Austria will introduce preventive detention for people convicted of terror offences following the deadly terrorist attack in Vienna last week, Chancellor Sebastian Kurz said Wednesday.

Even if people have served their sentences for terror offences, but are not yet seen as being completely deradicalised, "we will make it possible to lock those people up in order to protect the public," Kurz told a news conference after a cabinet meeting.

In some cases, people who have just been released will be monitored with an electronic ankle bracelet or a wristband, Kurz said, without explaining exactly when this particular method would be used or when preventive detention would be applied.

The measures are part of a package to be put to MPs for approval in December.

"It is a strong intervention, but, from my point of view, a necessary step to minimise the threat to our population," Kurz said, calling people like the Austrian-Macedonian dual national who killed four people last week "ticking time bombs."

Kurz also said there were plans to strip dual citizens convicted of terrorism offences of their Austrian citizenship.

The Vienna attacker had been jailed for trying to travel to Syria to join the Islamic State and was released early on condition he take part in a deradicalisation programme.

People convicted of terror-related offences could also be stripped of welfare benefits and have their driving licence taken away from them, Kurz said.