Nicholson said Afghanistan is better off for Canada's commitment, but he reiterated the military component will end in March.
"We have been very clear and we have been clear to all of our allies that we are removing our troops," said Nicholson.
But he said Ottawa has also committed to providing the Afghan military with just over $300 million worth of support over three years after its current training mission ends.
"There are a number of countries that are looking at what's taking place in Afghanistan . . . and we can be very proud of our efforts," Nicholson said.
He made the comments at a news conference wrapping up a three-day international security conference in Halifax.
The U.S. meanwhile, wants Afghan president Hamid Karzai to sign a security deal before the end of this year that would extend the American combat commitment past 2014.
But Karzai says he won't sign the deal until next April's elections, putting in doubt whether the U.S. will keep troops in the country.
During the Halifax conference U.S. Secretary of Defence Chuck Hagel said he needed the deal signed and ratified by the Afghan parliament before recommending to President Barack Obama that U.S. soldiers continue to risk their lives there.
The security pact would keep about 8,000 U.S. troops in Afghanistan until 2024.
The force would primarily train and mentor government security forces battling the Taliban insurgency.
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