The return home of the last Westerner to be held at the US naval facility in Cuba is problematic for the Canadian government, which had until now refused to say if it was willing to allow his repatriation.

"The government of the United States has accepted that Omar Khadr return to Canada and we will carry out the (plea) agreement between Mr Khadr and the US government," Foreign Minister Lawrence Cannon told the House of Commons.

Advertisement: Story continues below A US military tribunal sentenced Toronto-born Khadr to 40 years in prison on Sunday after he pleaded guilty to throwing a grenade that killed a US sergeant in Afghanistan in 2002.

The sentence was only symbolic as Khadr's lawyers had brokered a plea deal that meant his actual sentence was only eight years - including a provision that he could seek a transfer to Canada after an initial year at Guantanamo.

Once back in Canada, Khadr, who is now 24, would be eligible to apply for full parole following the completion of one-third of his sentence - an independent parole board would determine whether to release him.

University of Montreal international law professor Stephane Beaulac suggested Khadr could even be out within a few months and would probably contest the validity of the US prosecution upon his arrival in Canada. Continued...