A Canadian accused of killing an American soldier as a teenage al-Qaida militant pleaded guilty Monday as part of a deal that avoids a war crimes trial for someone labeled a "child soldier" by his defenders.

Omar Khadr pleaded to five charges including murder for throwing a grenade that mortally wounded the soldier during a fierce raid on an al-Qaida compound in Afghanistan in 2002. The now 24-year-old defendant also admitted to planting improvised explosive devices and receiving weapons training from the terrorist network.

The exact terms of the plea agreement were not immediately disclosed. Khadr will now face a military jury for a sentencing hearing that is expected to last several days. The panel cannot impose a sentence more severe than the plea agreement. His trial had been scheduled to start Monday and he faced a possible life sentence.

Dressed in a dark suit instead of the solid color jumpsuits typically worn by prisoners held at the U.S. base in Cuba, the defendant, who was born in Toronto and speaks fluent English, repeatedly answered "yes" to a series of questions from the military judge making sure he understood the charges against him.