"It wouldn't be a novel observation to say it doesn't appear to be going to plan," she told a press conference Monday.

New Zealand has so far refused to join the US-led coalition, preferring to back a United Nation's led effort.

Clark said war gaming ahead of the conflict had anticipated less resistance. The supply lines were vulnerable and more troops had to go in.

She said one of the government's key concerns had been that the war would act as a catalyst for the recruitment of young, bitter, frustrated and angry people in the Middle East.

"That is of considerable concern," she said.

"Certainly the suicide bombing of the American troops is a new development, and I would think poses considerable difficulties for the occupation of Iraq because with suicide bombings, every civilian in effect becomes a suspected belligerent and you're dealing with quite a different circumstance.

"That is a worrying trend."

WAR.WIRE