Questions are being raised, over when New Zealand troops will be able to leave Afghanistan and Iraq.

Only weeks after extending the Iraq deployment, it's now also being extended in Afghanistan, until June 2018.

MORE: Govt extends NZ's military deployment in Afghanistan until 2018

The Government won't rule out further extensions.

Labour's defence spokesperson Phil Goff said it shows the dangers of becoming involved.

"I think inevitably you get Mission Creep, go in thinking this is a job we can do, we'll be here two or three years. We've now been in Afghanistan for 15 years."

The Government says the extension in Afghanistan is "absolutely not" because of any international pressure.

Defence Minister Gerry Brownlee said our allies didn't ask us to.

"But we need to be sure that we're part of the coalition if for no other reason to show be as safe as they possibly can be in what is a increasingly uncertain world."

But Mr Goff isn't buying it.

"What you're seeing is a product of quite considerable pressure on New Zealand from other countries including the United States, Australia, the United Kingdom."

Mr Brownlee said we're making progress, but there's more work to be done, and we'll remain until it's finished.

"The history here is such that we're not going to walk away and allow the very rat bags who cause such a problem in that part of the world to take over."