U.S. Secretary of State Hillary Clinton called Foreign Affairs Minister Lawrence Cannon on Friday to discuss the case of Canadian-born prisoner Omar Khadr, sources told CBC News.

Canadian Omar Khadr attends a pretrial hearing at the U.S. naval base in Guantanamo Bay, Cuba, in August as seen in this courtroom sketch, which was reviewed by the U.S. military. (Janet Hamlin/Pool/CBC)

Representatives of Cannon and the U.S. State Department confirmed the two spoke on the telephone while the foreign affairs minister was in China, though neither would say what topics were discussed.

But sources told the CBC's James Cudmore that the call was about Khadr, who has spent eight years at the U.S. military prison in Guantanamo Bay, Cuba, awaiting trial on terrorism charges.

It comes just hours after Cannon dismissed reports he has spoken directly with Clinton about repatriating the Toronto-born Khadr.

"It's not up to me to determine how the U.S. government is going to be working in this case," Cannon said in interview with CBC News on Friday from Beijing. "These are issues, of course, that are of concern to the United States. It deals with their judicial system, their legal system."

CNN has reported that Clinton is getting involved to arrange a deal that would see Khadr, 24, plead guilty to murdering an American soldier during a firefight in Afghanistan in 2002.

A source close to the talks said Khadr must decide whether to sign on to a deal negotiated by prosecution and defence lawyers that would have him serve one year in U.S. custody and seven more in Canadian custody.

Nate Whitling, Khadr's Canadian lawyer in Edmonton, told CBC News last week that a potential deal is in the works but he couldn't comment on the details.

Khadr is the first person in more than 60 years to face a U.S. military tribunal for crimes allegedly committed as a minor.

With files from The Canadian Press