NDP Leader Jack Layton called for a debate on Canada's mission in Afghanistan as Prime Minister Stephen Harper made a surprise visit to troops in the region.

"A debate in Parliament really should take place regarding the role that Canada is playing in Kandahar, and what the future holds for Canadian involvement in that part of the world," Layton told CTV Newsnet on Sunday.

He added that "all of the issues" should be discussed regarding the mission, including the role of Canadian troops, their relationship to American operations in Afghanistan, the length of the mission and its cost.

Layton also argued that a vote on the mission should naturally follow such a debate, possibly giving critics a chance to decide whether troops should remain in Afghanistan.

"At some point of course there really should be some sort of a vote," Layton said.

"In fact, Mr. Harper and Mr. (Gilles) Duceppe favoured the concept that when Canadian troops are deployed abroad there should be a vote at some point regarding that deployment and its future. It's very common … in this part of the world."

Layton did not say if his party would support a lengthy mission in such a vote, saying there was not enough information about the mission to make a proper decision.

However, he said Canadians want to know that troops in Afghanistan are not following the policies set by U.S. President George W. Bush to combat terrorism, but are operating under the values of their own country.

"It's not a question about being weak-kneed, it's a question of what is Canada's role internationally," Layton said.

"We know that Canadians are not comfortable with some of the approaches taken by George Bush and his administration. We want to ensure that this is an independent foreign policy being exercised here in conjunction with the international community in proper fashion. We've always looked to the (United Nations) for direction."

Drapeau calls visit 'unprecedented'

However, Colonel Michel Drapeau, former director general for the Department of National Defence, said Harper's visit to Afghanistan shows that Canada no longer has a "politics of neutrality."

"It's unprecedented. I can't recall an instance where the head of government … would deploy to the front trenches and bring his minister of defence along to meet the troops," he said.

"It's a brave and very bold move and it's leadership at its very best. Years from now we will look back at this day as a turning point … because it shows that Canada has basically shifted gears. We went from a policy or a politics of neutrality … and here we have a prime minister newly elected, with his minister of defence, making a huge statement to allies."

Drapeau said the visit will greatly boost the morale of troops, who will now know that "the Canadian government, through the mouth of the prime minister, is squarely behind them."