NZ 'highly unlikely' to send SAS to Iraq

It is "highly unlikely" SAS troops will be deployed to Iraq despite a request from the US for more assistance in the fight against Islamic State (IS), Prime Minister John Key says.

Overnight, American defence secretary Ash Carter told a senate committee the US was increasing its military role in Syria and Iraq, and he called on other countries to do the same.

"The international community, including our allies and partners, has to step up before another attack like Paris," he said.

Defence Minister Gerry Brownlee confirmed to RNZ he received a letter from Mr Carter on Friday requesting more help.

Mr Brownlee said it was a generic letter that mentioned assistance with airstrikes, ammunition, special forces troops and training.

But Mr Key this afternoon said it was "unlikely" much would change regarding New Zealand's contribution.

He said they would take time to consider the request but it would be a "very big call" to have troops accompanying the local Iraqi forces.

"My inclination is that we're making a big enough contribution already in Iraq... and in the end we're only a small country."

More than 100 New Zealand Defence Force (NZDF) personnel are in Taji, north of Baghdad - largely to train the local security forces.

'Political will'

Victoria University professor of strategic studies Robert Ayson said New Zealand could do more if the government wanted to.

A lack of voter appetite for getting involved and concern the fight was becoming increasingly long-term would be holding them back, he said.

"I don't think the judgment is about capacity in a physical sense... but the issue is not capacity, it's political will and I think the government thinks it is doing enough, it's doing enough to show it is part of the coalition."

A review of New Zealand's involvement in Iraq was already underway and will be presented to Cabinet in March.

The government is unlikely to make a formal decision on the American request before then.