NATO is moving to shore up troop security in Afghanistan after a series of deadly attacks by Afghan forces on its soldiers.

The attacks are "very insidious, very demoralizing and very tragic, to say the least," Defence Minister Peter MacKay said Friday in an interview with QMI Agency.

MacKay was in Europe following the two-day NATO defence ministers meeting in Brussels.

"One of the takeaways from this meeting was a specific initiative where NATO is going to be tasking a group in Afghanistan to ensure a more robust vetting system," he said.

"That is a filtration system that picks up either Taliban infiltration or the type of instability, aggressiveness, animosity that results in these incidents."

France suspended training and support operation in Afghanistan in January after a rogue Afghan trainee killed four French soldiers.

American and Australian forces have also been killed in what the military calls "green-on-blue" attacks -- where Afghan forces turn on their International Security Assistance Force (ISAF) trainers.

MacKay said General John Allen, in charge of Afghanistan ISAF troops, told the NATO meeting he was making troop security a priority in the wake of the deaths.

"He has people now in place looking for more protections for our trainers and putting a system in place that is going to close the loop on who finds their way into these training bases and putting greater protections there for the trainers themselves," MacKay said.

Ottawa has committed some 950 Canadian Forces personnel to a training mission in Afghanistan centred in Kabul after ending its combat mission in 2011.

--with files from Reuters