The Federal Government would be able to put troops on Perth streets if police needed help dealing with a terrorist attack, under new rules to be introduced by Prime Minister Malcolm Turnbull.

And State governments faced with terrorists who take hostages would be able to call on special forces units such as the Special Air Service Regiment immediately under the changes, introduced partly in response to criticism of the way NSW police handled the Lindt cafe siege in December 2014.

The new engagement rules will be announced by Mr Turnbull in Sydney this morning, and include ways of improving law enforcement agencies’ response to terrorist attacks.

State governments will be able to call on help from the Australian Defence Force immediately under changes to the Defence Act.

Currently, governments have to wait until they know their own capability or capacity to respond has been exceeded before they can ask for assistance.

And the military will offer to take a bigger role in training and assisting specialist police anti-terrorism units, such as the tactical response group in WA, to ensure they are prepared for attacks.

That will include an offer of training from ADF special forces units such as the SAS, which is based in Swanbourne.

It could also include embedding military officers in local police to improve the information flow between State and Federal authorities.

Mr Turnbull told The West Australian details of the rules would be thrashed out with States and Territories at Council of Australian Governments meetings, and through the Australia-New Zealand counterterrorism committee.

“Together, these measures will improve the nation’s ability to respond to terrorism as well as improve the effectiveness of Defence’s contribution to domestic counterterrorism arrangements,” he said.

Mr Turnbull said State and Territory police forces would remain the primary responders to terrorist attacks, but the overhaul would allow the Federal Government to offer more support to local authorities, and mobilise faster in the event of a major incident.

“It is essential that Australia evolves its responses and countermeasures in response to the changing threat,” he said.

“Defence must be able to contribute effectively to domestic counterterrorism efforts, in addition to its offshore counterterrorism missions and regional capacity-building activities.”

SAS file photo. Picture: AP Photo/Firdia Lisnawati)