Defence Minister Peter MacKay said Canada has the option of waiting until April 2008 before choosing whether to extend its mission in Afghanistan, despite pressure from opposition parties for an early decision.

Bloc Quebecois Leader Gilles Duceppe has said he wants the government to include firm plans for an end to the mission in its throne speech next month.

Otherwise, he has promised to vote against the speech, setting up a possible fall election.

On Monday, MacKay said Canada can wait until the NATO summit next year in Bucharest, Romania, before clarifying whether combat operations will continue past February 2009.

"There is a NATO meeting in April 2008," MacKay told reporters.

"It will be necessary to communicate a final decision before that meeting."

Liberal Leader Stephane Dion has also said he wants the government to clearly state in its speech whether it will extend the mission, while NDP Leader Jack Layton has repeatedly called for an immediate troop withdrawal.

If all three opposition parties vote against the throne speech -- considered to be a confidence vote -- the government will fall.

Liberal MP Denis Coderre told The Canadian Press that April 2008 is an artificial deadline.

"So just because there's going to be an announcement at a conference in Romania in 2008, does this mean now that Canadians shouldn't talk about it among themselves and decide for themselves?" he asked.

"This is nothing more than domestic politics."

MacKay said the Conservatives support the mission but that an extension will be decided in Parliament.

"I expect fully that there will be a lot of discussion about this over the fall -- just as we're seeing in other parliaments," he said.

He also said that opposition parties can table a motion to force a vote.

"The mission has a parliamentary mandate to go until February of 2009," he told reporters. "We've also been equally clear in saying that anything beyond that has to have the support -- the majority support -- of the Parliament of Canada."

Canada has lost 70 military personnel and one diplomat in Afghanistan since the mission began, and the war is expected to cost $6 billion by 2009.

Last week, Afghan President Hamid Karzai called on Canada to maintain its military presence in Afghanistan, saying his country will fall into the hands of terrorists without Canada's help.

But he also acknowledged that Canada has suffered a high level of casualties compared with other NATO allies in the country.

"Canada is one of the greatest contributors to Afghanistan's reconstruction and peace-building and institution building," he said. "It's given us a lot. It's given the life of its sons and daughters in Afghanistan."

With files from The Canadian Press