Qatar has welcomed the release of US and Australian university professors who were held in Afghanistan, as well as the release of a number of Afghan detainees.

Quoting a Foreign Ministry statement on Thursday, the official Qatar News Agency (QNA) said the State of Qatar, in addition to its intensive efforts as a mediator in the peace talks between the United States and the Taliban, has played an active role in facilitating the release of detainees and ensuring continued cooperation between all parties concerned.

"Qatar sees the exchange of detainees as a goodwill gesture from the Afghan government and the Taliban to move forward with peace talks and make progress to end the war in Afghanistan," the QNA report said.

Qatar thanked all parties concerned for their continued co-operation to release the detainees, while congratulating the US and Australian professors' families on their safe return.

The statement reaffirmed Qatar's commitment to achieving lasting peace in Afghanistan through continued mediation efforts.

AFP adds from Frankfurt am Main: Two Western hostages held for three years by the Taliban in Afghanistan landed in Germany on Thursday after a prisoner exchange two days earlier, a US diplomat confirmed.

American Kevin King and Australian Timothy Weeks landed overnight at the US Air Force's Ramstein airbase in western Germany, and would be staying nearby "for a period of evaluation and reintegration," the US official said.

King and Weeks, both professors at the American University (AUAF) in Kabul, were kidnapped by gunmen wearing military uniforms in the heart of the Afghan capital in August 2016.