The U.S. military has laid formal charges -- including one of murder -- against Omar Ahmed Khadr, a Canadian citizen imprisoned at the U.S. military prison for suspected terrorists at Guantanamo Bay, Cuba.

Khadr, 19, is "charged with conspiracy to commit offences triable by military commission; murder by an unprivileged belligerent; attempted murder by an unprivileged belligerent; and aiding the enemy," said a U.S. Defense Dept. news release on Monday.

An "unprivileged belligerent" is someone who isn't a member of a regular army, one of Khadr's Canadian lawyers, Nathan Whitling, told CTV.ca on Monday.

Some of those charges could leave Khadr facing the death penalty.

"The U.S. has not taken the death penalty off the table. The Canadian government has formally requested that they do so many times, and they still haven't done so," Whitling said.

Khadr will face a military trial under a U.S. military commission. Critics have raised concerns about the commissions, saying they do not give detainees the same rights as civilian courts and that they violate the Geneva Convention.

The U.S. Defense Department says Khadr has the presumption of innocence, has the right not to testify without inference of guilty and must be proven guilty beyond a reasonable doubt.

While the U.S. government will provide counsel, Khadr has the right to civilian counsel, but at his expense.

However, Whitling said there are major procedural issues with these military commissions.

Some of those issues will be decided in a U.S. Supreme Court case involving Salim Ahmed Hamdan, a former driver for al Qaeda leader Osama bin Laden, who is being held in Guantanamo Bay. The U.S.'s highest court agreed Monday to hear the case.

Here are some of Whitling's concerns:

• The use of secret evidence and the ability of the commission to hear such evidence in the absence of both the defendant and his counsel
• The fact Omar Khadr committed his alleged crimes when he was only 15
• The application of torture at Guantanamo Bay and the fact that any such evidence gathered would be admissible.
• Khadr was denied counsel while being interrogated
• His capacity to respond because his physical and mental health have deteriorated
• The lengthy delay between the alleged offence and the date charges were laid.
• Limited ability to marshall evidence and call witnesses

Canadian government officials say they will be closely watching the case and will take legal steps to make sure the teenager's rights are upheld.

"Foreign Affairs Canada is very aware of this case for obvious reasons," Dan McTeague, parliamentary secretary for Canadians abroad, told Canada AM Tuesday.

"We've had some visits with him in Guantanamo Bay. What's important for us at this point is to ensure that he has access, obviously, to appropriate legal counsel so that he does have an opportunity to defend his case appropriately under international law."

Arrested in Afghanistan

Khadr, 19, was born in Toronto. His family moved to Peshawar, Pakistan when he was four.

He was arrested in Afghanistan by the U.S. military in 2002, when Khadr was 15. They declared him an enemy combatant and shipped him to Guantanamo Bay.

He is accused of throwing a hand grenade at U.S. soldiers. One soldier died in the alleged attack and three others were wounded, with one soldier losing an eye.

Late last month, a Utah judge issued a default judgment against the estate of Ahmad Sa'id Khadr, Omar's father. The lawsuit alleged the elder Khadr, a Canadian citizen, was an al Qaeda financier who failed to control his son.

Ahmad Khadr died in a 2003 gun battle with authorities in Pakistan province of Waziristan, which is next to the border with Afghanistan. His youngest son Karim was left paralyzed after being struck by a bullet.

Karim's mother brought her son back to Canada for treatment in the fall of 2004.

Ahmad's eldest son Abdullah is on the run, while Abdurahman Khadr is on the outs with his family after admitting to being a mole at Guantanamo Bay.