The US military is now conducting cyber attacks on the Islamic State (IS) group, a general has confirmed, as the Pentagon looks to accelerate the fight against the jihadists.

A US-led coalition of warplanes has been striking IS targets in Iraq and Syria since August 2014, and officials have long stated the importance of using cyber techniques such as overloading IS networks to limit the group's communications and ability to reach potential new recruits.

"We have now begun to use our exquisite cyber capabilities in this fight," Baghdad-based Major General Peter Gersten told Pentagon reporters.

He did not elaborate, except to say the effort is "highly coordinated" and has been "very effective".

In February, Defence Secretary Ashton Carter and the US military's top officer General Joe Dunford said the United States was determined to "accelerate" the anti-IS campaign, and indicated cyber warfare would play an increasingly important role in doing so.

Earlier this month, Deputy Secretary of Defense Robert Work said: "We are dropping cyberbombs" on the IS group.

The New York Times said the US Cyber Command had placed "implants" in IS networks that let experts monitor the group's behaviour.

It said the US hoped to ultimately imitate or alter commanders' messages so they unwittingly direct fighters to areas likely to be hit by drone or plane strikes.

Last week, Prime Minister Malcolm Turnbull also admitted for the first time that the Australian Government had the ability to launch cyber attacks, saying "an offensive cyber capability housed in the Australian Signals Directorate provides another option for Government to respond".

It came as Mr Turnbull confirmed the Bureau of Meteorology had been hacked.

US Cyber Command engaged in Baghdad

The US Cyber Command is charged with protecting America's military and some civilian networks from attacks, as well as deploying its own offensive cyber strategies if needed.

By 2018, it will have more than 6,000 military and civilian technical experts working across 133 teams.

One such team, comprising about 65 people, works in the Middle East and carries out cyber operations against IS networks.

Admiral Michael Rogers, head of both Cyber Command and the National Security Agency, declined to provide any additional information on Tuesday.

"We have publicly acknowledged that we are using cyber as another tool against ISIL," Rogers said at a Georgetown University cybersecurity conference, using an acronym for the IS group.

"I want them to be aware: We are going to contest you on the kinetic battlefield, we are going to contest you with information dynamics, we are committed to this fight," he added.

AFP