Two Canadian diplomats freed from captivity in Western Africa have been transferred into Canadian custody and are in good physical condition.

Robert Fowler and Louis Guay first went missing on Dec. 14, when their car was found abandoned 50 kilometres northeast of Niamey, the capital of Niger.

The men, now sporting long white beards, attended a reception at the presidential palace in Mali Thursday, where they thanked the African countries that assisted Canada in their release.

"They seem tired but they are doing OK," Diarra Diakite, spokesperson for the president of Mali said.

Mali President Amadou Toumani Toure said he considered it a moral duty to help the captured Canadians, because Mali is one of Canada's biggest recipients of foreign aid.

Fowler and Guay plan to make several stops in Africa to thank the governments that assisted in their release.

Prime Minister Stephen Harper spoke to the two diplomats Thursday, a day after they were freed in northern Mali.

Harper told the men he was relieved that they were safe following their four-month ordeal.

A government official told The Canadian Press that neither man was beaten or physically harmed during their capture, but they were subjected to a "terrible ordeal."

"There's no indication of any physical torture," said the government official.

"We are a bit concerned about the mental or psychological abuse they may have endured."

Harper's office said Fowler and Guay will soon be meeting up with their families and will then fly home on a Canadian government aircraft.

Liberal MP Dominic Leblanc, a distant relative of Fowler, said the diplomat would meet his wife and four daughters in Europe.

It's unclear how the two men were freed from their abductors, but the release was secured by officials in Mali and Burkina Faso, which both border Niger.

On Thursday, UN spokesperson Farhan Haq said Canada played a major role in working to ensure their safe release.

"Both the Canadian government and the United Nations consulted widely among governments in the region making sure all the various governments in the region could bring their influence to bear to make sure that whoever was holding them, the abductors, would understand the need to release them safely," Haq told CTV Newsnet.

Harper said Wednesday that Canadian officials had never offered to pay the abductors any money for the diplomats' freedom.

Diakite said that Mali paid no ransom money either.

Fowler had been appointed as the UN Special Envoy to Niger, and Guay was working as his aide.

In January, Niger's president said the diplomats had been taken by rebels, and the following month the North African branch of al Qaeda -- known as al Qaeda in the Islamic Maghreb -- claimed responsibility for their abduction.

Lloyd Axworthy, former foreign affairs minister, said the UN diplomats face a real issue of support and security in Africa.

"For a long time I've really argued that the United Nations needs its own... force so that in dangerous situations it can provide a level of protection for those who are trying to negotiate or work on its behalf," Axworthy told CTV Newsnet on Thursday from Turkey.

When asked if there was an issue regarding safety, UN Spokesperson Vannina Maestracci told CTV Newsnet that "the UN takes security of its staff very seriously."

Fowler has had a long career in public service, working for Canada and the UN. He previously served as Canada's ambassador to Italy, as a former deputy defence minister, and is a senior fellow at the University of Ottawa's Graduate School of Public and International Affairs.

Louise Frechette, a former United Nations deputy secretary-general and long time Canadian diplomat, said she felt "great relief" when she heard her friend, Fowler, and Guay were released.

"These people are capable of everything, so to know that he came out of this ordeal safe, and as far as I can tell from the photos, he's still himself, I feel really quite happy," she told CTV Newsnet Thursday evening.

Frechette said Fowler was passionate about Africa and has a "life-long commitment to the continent."

Paul Heinbecker, former Canadian Ambassador and Permanent Representative to the United Nations, said Thursday that Fowler was of "very strong character" with "enormous intellectual capabilities."

With files from The Canadian Press