Omar Khadr, 22, has been imprisoned in the U.S. military prison in Guantanamo Bay, Cuba, since October 2002. He is alleged to have thrown a grenade that caused the death of a U.S. soldier. (Janet Hamlin/Associated Press)

The Supreme Court of Canada has agreed to hear the federal government's appeal of a ruling forcing Ottawa to press for the release of Canadian Omar Khadr from Guantanamo Bay.

As is customary, the court gave no reasons for its decision Friday morning.

Last month, the Federal Court of Appeal upheld a lower-court ruling that required Ottawa to try to repatriate 22-year-old Khadr, the only Western citizen still being held by the United States at its military base in Cuba.

Opposition parties decried the decision to appeal, saying it goes against the government's legal and moral obligations toward its own citizens. Khadr's lawyers called the government's decision "mean-spirited" and argued the top court should not hear the appeal.

Lawyers for the government have argued that only the prime minister and cabinet should have the authority to make decisions regarding foreign policy.

Government's position unchanged

Justice Minister Rob Nicholson would not answer questions Friday on the decision.

But in a statement, Canada's Foreign Affairs Department said the federal government's position on Khadr's case remains unchanged and that Ottawa has consistently stated that he faces serious charges.

"As the matter is currently under litigation, we will provide no further comment at this time," said the statement released by Foreign Affairs Minister Lawrence Cannon's spokeswoman, Catherine Loubier.

The statement then went on to state the government's position that it was in Canada's "interest" to wait for the United States to make a decision on Khadr's case.

"As you know the Obama administration has recently taken decisions to proceed with the closure of Guantanamo, halt the judiciary process and also to evaluate each of the cases," it said. "It is in our interest to wait for the outcome of these decisions just put forward by President Obama.

"The government of Canada has taken its responsibilities with regards to Mr. Khadr, and we will also take our responsibilities when the U.S. government shares its decision on this case."

Liberals would press for return

At a news conference in Vancouver Friday, Liberal Leader Michael Ignatieff said he would press to bring Khadr home if his party wins a federal election that could come as early as October.

"We find it extraordinary that the Conservative government would take this right up to the Supreme Court when we're talking about a Canadian citizen," Ignatieff said.

"Canadians have different views about Mr. Khadr's conduct. But that's not the issue. This man is a Canadian citizen. Guantanamo needs to be closed. Canadians think we should play our part in closing Guantanamo."

Toronto-born Khadr was captured by U.S. soldiers in Afghanistan in 2002, when he was 15, and has been held at the Guantanamo Bay detention centre for seven years. The U.S. accuses him of throwing a grenade that killed U.S. soldier Christopher Speer, but leaked documents have called into question the Pentagon's murder case against Khadr.

Khadr has been stuck in legal limbo since the swearing in of U.S. President Barack Obama, who vowed to close Guantanamo and repatriate all but its most serious prisoners.

But the Obama administration has yet to clarify its intentions for Khadr, and it now appears the controversial military tribunals at Guantanamo might still proceed.

Appeals court ruled Khadr's charter rights violated

In a 2-1 judgment in August, the appeal court agreed with a Federal Court judge's ruling that Khadr's rights under Section 7 of the Charter of Rights and Freedoms — the rights to life, liberty and security of person — had been breached when Canadian officials interviewed him at the prison in Guantanamo in 2003 and shared the resulting information with U.S. authorities.

Some other Western countries have intervened to get their citizens out of Guantanamo but the Canadian government has maintained that Khadr should face military proceedings in the United States due to the serious nature of the charges.

The Conservatives have also argued they are being consistent with the position of previous Liberal governments that refused to intervene and seek Khadr's repatriation.

The appeal court also dismissed the claim that there is little chance the U.S. will abide by the repatriation request, since the U.S has complied with similar requests from other Western countries.

The Supreme Court will hear arguments in the case on Nov. 13.