A former Guantanamo Bay inmate, free for the first time since he was captured in Afghanistan when he was 15, has asked Canadians for a second chance after spending 13 years in prison, including a decade at Guantanamo.

A relaxed and smiling Omar Khadr said freedom was way better than he thought and said he wanted a fresh start.

Khadr was released on bail after a judge refused a last-ditch attempt by the Canadian government to keep him imprisoned.

Toronto-born Khadr spent 10 years in the US prison at Guantanamo Bay, Cuba. Since 2012 he has been held in Canada, serving out an eight-year sentence handed down by a US military commission in 2010.

He was convicted of war crimes, including throwing a grenade when he was 15 that killed US Army sergeant Christopher Speer in Afghanistan during a 2002 firefight.

Khadr, now 28, was once the youngest detainee at Guantanamo.

Omar Khadr listening to a question during a news conference after being released on bail in Edmonton, Alberta. Photo: Todd Korol/Reuters

“Give me a chance to see who I am as a person, not as a name,” he said outside his lawyer’s home in Edmonton, Alberta. “I’ll prove to them that I’m a good person.”

Defense lawyers said Khadr was a child soldier who was pushed into war by his father, Ahmed Said Khadr, an alleged senior al-Qaeda financier whose family stayed with Osama bin Laden briefly when Omar was a boy. His Egyptian-born father was killed in 2003 in a Pakistani military operation.

Khadr, articulate and showing no bitterness, said he believed in education and was excited to start his life.

Asked what he had to say to Americans, Khadr said: “I’m sorry for the pain I’ve caused for the families of the victims. There’s nothing I can do about the past but I can do something about the future.”

... in Guantanamo Bay’s Camp 4 in October 2010. Photo: Colin Perkel/The Canadian Press

Khadr said he would disappoint Canadian prime minister Stephen Harper, whose government has long refused to do anything for him while he was at Guantanamo and has tried to keep him in prison in Canada.

“I’m better than the person he thinks I am,” Khadr said.

Khadr was the last Western detainee at Guantanamo. Asked if he categorically rejects violent jihad, he said “Yes, yes I do.”

“It’s not something I believe in right now. I want to start fresh. There are too many good things in life that I want to experience.”

Khadr said he noticed a lot of people are able to be manipulated if they are not educated and wants to finish his education and work in healthcare. “I have a lot of basic skills I need to learn,” he said.

Khadr also pleaded guilty in 2010 to building and planting roadside bombs and receiving weapons training from al-Qaeda in a widely-criticised trial that made the US the first Western nation since the World War II to prosecute a child offender for alleged war crimes.

Court of Appeal judge Myra Bielby earlier rejected the Canadian government’s emergency request to stop Khadr release’s while he appealed against his US war crimes conviction. A lower court judge granted him bail last month.

Khadr’s long-time lawyer Dennis Edney and wife have offered to take him into their home. Among the bail conditions imposed were that Khadr wear a tracking bracelet, live with the Edneys, observe a curfew between 10pm and 7am and have only supervised access to the internet.

Also, he must communicate with his family in Ontario only while under supervision and only in English.