OTTAWA - Canadian troops should stay to train the fledgling Afghan army beyond the official pullout next year, says an outspoken former general.

And retired major-general Lewis MacKenzie told a House of Commons committee that rumblings from the Liberals make him hopeful a training assignment in Kabul -- where Canadian troops give classroom instruction to Afghan soldiers -- will come about.

"I'm heartened by the fact there seems to be some agreement that that would be an ideal role for us," said MacKenzie, who commanded UN forces in Sarajevo during the Balkans war.

The Canadian army is exhausted and the combat mission in Kandahar must come to an end, he said, but that should not mean a halt to Canada's military involvement.

MacKenzie told MPs a future deployment should not involve soldiers embedded with Afghan troops in the field, in units known as Operational Mentoring and Liaison Teams.

"I've read Canadian public opinion and I guess I've become a realist, but I really want us to leave something behind," he said.

"The OMLTs may be a bridge too far. I've said over and over, people in the U.S. ... don't know we're in Afghanistan, but when that last piper plays and the ramp comes up on the C-17 (transport plane) and we leave -- everybody will know we've left. So this would temper that."

Earlier this week, Liberal Leader Michael Ignatieff made continued engagement in Afghanistan part of his party's new foreign policy. An all-party Commons committee recently returned from the war-ravaged nation with a similar message.

A parliamentary motion passed in March 2008 instructs the army to end combat operations in Kandahar by July 2011, and complete withdrawal from the area within six months.

But Prime Minister Stephen Harper added that the army would leave Afghanistan entirely. He has maintained that position, despite pressure from Washington to stay and from some of his own ministers for a non-combat military mission.

Asked in the Commons this week whether he accepts Ignatieff's proposal, Harper surprised the NDP by not categorically restating the government's withdrawal plans.

New Democrat Leader Jack Layton read a lot into that omission.

"I thought it was very interesting that the prime minister ducked the whole issue of whether he'd support the Liberal party's position that we should extend our troop involvement in Afghanistan post-2011," Layton said.

"I gave him more than one opportunity and he chose not address it. I think Canadians should be concerned the two old parties are beginning to work again to see an extended presence of our troops in Afghanistan. That certainly worries us."

The Commons defence committee is looking at the military's role in foreign policy post-2011.

MacKenzie warned that Ottawa should be selective on the peacekeeping missions it chooses. He said it should pick only those deployments where both sides have clearly stated they're tired of fighting.