During their deployment, SAS troops have conducted operations against insurgent networks, predominantly improvised explosive device and suicide bomber networks.
They have also provided counter-terrorism help to the Afghan police's crisis response unit.
Dr Coleman said this was a direct response to the international community's goal of increasing the capacity and capability of the Afghan security forces.
He acknowledged the loss of Corporal Douglas Grant and Lance Corporal Leon Smith, who were killed last year in separate operations.
"They were brave men who made the ultimate sacrifice in the service of New Zealand. Our thoughts continue to be with their families and colleagues.''
The families of the two men have been been presented with the New Zealand Memorial Cross, while Lance Corporal Smith was also posthumously awarded the Charles Upham Award for Bravery.
The Labour Party has been critical of the decision to redeploy SAS troops in 2009, saying it would be wrong to support a government that did not have the trust of its people.