The government is appealing a Federal Court judge's ruling that Canada must press the United States for the return of Omar Khadr from the Guantanamo Bay detention centre, officials confirmed Friday.

Federal officials have filed an appeal of Justice James O'Reilly's ruling that Canada must "present a request to the United States for Mr. Khadr's repatriation as soon as practicable."

Khadr is accused of killing a U.S. soldier with a hand grenade during a gunfight in Afghanistan in 2002. Khadr, now 22, was 15 at the time he was detained in Afghanistan.

In the Federal Court decision issued last month, the judge pointed out that Khadr is the last citizen of any Western country held at the Guantanamo Bay detention centre. Other countries have repatriated their citizens.

The U.S. and Canadian governments are signatories to a United Nations protocol that states fighters under age 18 are to be considered child soldiers and must be released and helped to reintegrate into society.

Like all Guantanamo prosecutions, Khadr's case is on hold pending a review by U.S. President Barack Obama's administration.

With files from The Canadian Press