"That could be anything from everything from the form of people going in and training right through to ultimately people that would be there right on the front line."
My Key declined to reveal what his preferred option would be.
"We have to be very careful and cautious about what we do."
"The real issue here - and it's a legitimate question for New Zealanders to ask - is should New Zealanders get involved?"
"There are definite risks there. I don't want to overstate those risks, but they are there. They're risks in terms of foreign fighters in New Zealand and they're either looking to leave or return.
"We're trying to get to a point where I can declassify that number to spell that out for people."
View: PM: Isis fight - NZ won't be a target
It would be "odd" for New Zealand did not join the fight against ISIS when so many of our major trading partners were already involved, he said.
"If you don't stand up to a known terrorist group that is dangerous and growing at a frightening rate, if the reason you don't do that is because you feel intimidated by them then by definition, they are starting to control your foreign policy."
Mr Key said other priorities this term included passing National's employment law reform bill, which fell over at the last term due to the resignation of National's support partner John Banks.
"I think the law is a tidy up of some scenarios which need reform."Reforming the Resource Management Act was another priority, Mr Key said.
PM accused of scaremongering
Meanwhile, an international security expert has accused the Prime Minister of "scaremongering" to build a case for war by claiming New Zealand could face domestic beheading threats.
John Key also told TV3's The Nation yesterday that a disproportionate number of Islamic State fighters were sourced from in and around Oceania.
International security expert Paul Buchanan said the claims were "absurd". "He's building a case for war. He's pulled the beheading imagery out for what I think are spurious purposes."
Buchanan accused Key of misrepresenting New Zealand's role in joining the coalition against Isis - although he conceded it was impossible to discount a threat. "There's no evidence that because you fight against Isis the method of retribution is beheading on the streets of Auckland."
He also rubbished the idea a "disproportionate" number of fighters were sourced here.
Key said terrorists returning to New Zealand were a possible security risk and he warned Isis posed a major risk to Kiwi aid workers based in the Middle East.
He told TV3 these reasons, and the growth of Isis, were among reasons New Zealand might join combat operations.
Key has said he would consider sending troops to counter Isis if called on by allies. Earlier this week he would not rule out sending the SAS. It would be odd for New Zealand to do nothing when its allies were involved in fighting back, he said yesterday.
"The question is what we do, rather than whether we do something."
Islamic militants have beheaded four Western hostages since mid-August, most recently 47-year-old English aid worker Alan Henning.
A fifth man - US native 26-year-old Abdul-Rahman Kassig - is being held in Syria and militants say he is next.
- with additional reporting by the Herald on Sunday
