Canada has called for the unconditional release of a Canadian man and his American wife after a new video appeared to show them begging their governments to intervene on their behalf with their Afghan captors.

The video, which was uploaded to YouTube on Monday, shows Canadian Joshua Boyle and American Caitlan Coleman, who were kidnapped in Afghanistan in 2012. The video showed for the first time the two sons of the couple.

Canadian Global Affairs spokesman Michael O'Shaughnessy said his government was aware of the latest video.

"We are deeply concerned for the safety and wellbeing of Joshua Boyle, Caitlan Coleman and their young children and call for their unconditional release," O'Shaughnessy said.

READ MORE: Progress and regress - Obama's mixed Afghanistan legacy

In the video Coleman refers to "the Kafkaesque nightmare in which we find ourselves" and urges "governments on both sides" to reach a deal for their freedom.

Afghanistan: Taliban fighters remain on Kunduz outskirts

"We can only ask and pray that somebody will recognise the atrocities these men carry out against us as so-called retaliation in their ingratitude and hypocrisy."

She then adds: "My children have seen their mother defiled."

On Tuesday, a senior Taliban figure confirmed to Reuters news agency the armed group released the new video showing the kidnapped family.

The US State Department said it was reviewing the footage.

The video came to public attention through the Site Intelligence Group, which monitors activities of armed groups online. SITE said it was dated December 3.

The two vanished after setting off in the summer of 2012 for a journey that took them to Russia, the Central Asian countries of Kazakhstan, Tajikistan and Kyrgyzstan, and then to Afghanistan. 

Coleman, 31, was pregnant when the couple was abducted.

Her parents, Jim and Lyn Coleman, last heard from their son-in-law on October 8, 2012, from an internet cafe in what Josh described as an "unsafe" part of Afghanistan.

In 2013, the couple appeared in two videos asking the US government to free them from the Taliban.

READ MORE: Canada allows female mounted police to wear hijab

The Colemans received a letter last November in which their daughter said she had given birth to a second child in captivity.

In July, Jim Coleman, speaking to the online news service Circa News, issued a plea to top Taliban commanders to be "kind and merciful" and let the couple go.

A video released in August showed Coleman and Boyle saying their captors would kill them and their children unless the government in Kabul ends its execution of Taliban prisoners.

Afghan Translators: Out of Hiding - Fault Lines

Source: News agencies