The transfer idea is part of US efforts to bring the Taleban to the negotiating table to avoid prolonged instability in Afghanistan after foreign combat troops leave the country at the end of 2014.

"We are hopeful this will be a positive step toward peace efforts," Karzai's spokesman Aimal Faizi said, adding the Taleban detainees would be re-united with their families in Qatar if the transfer takes place.

It would be one of a series of good-faith measures that could set in motion the first substantial political negotiations on the conflict in Afghanistan since the Taleban government was toppled in 2001 in a US-led invasion.

A year after it was unveiled, the Obama administration's peace initiative may soon offer the United States a historic opportunity to broker an end to a war that began as the response to the Sept. 11, 2001, Al-Qaeda attacks on the United States.

But the peace drive also presents risks for President Barack Obama.

He faces the potential for political fallout months before a presidential election, as his government considers backing an arrangement that would give some degree of power to the Taleban, known for their brutality.

Despite months of covert diplomacy, it remains unclear whether the prisoner transfer will go ahead.

Doubts are growing about whether the Taleban leadership is willing to weather possible opposition from junior and more hard-core members who appear to oppose negotiations.

Karzai's top aide, Ibrahim Spinzada, visited the Guantanamo facility this week to secure approval from the five Taleban prisoners to be moved to Qatar.

Karzai's government has demanded the five former senior members of the Taleban government, held at Guantanamo Bay for a decade, give their consent before they are transferred to the small Gulf state where they would be under Qatar's custody.

US officials hope the peace initiative will gain enough traction to enable Obama to announce the establishment of full-fledged political talks between the Karzai government and the Taleban at a NATO summit in May.

That would mark a major victory for the White House and might ease some of the anxiety created by NATO nations' plans to gradually pull out most of their troops by the end of 2014, leaving an inexperienced Afghan military and fragile government to face a still-formidable insurgency.

The Taleban detainees are seen by some US officials as among the most dangerous inmates at Guantanamo.

Their possible transfer has drawn attack from US politicians from both parties even before the administration formally begins a required congressional notification process.

Among the prisoners who may be sent to Qatar is Mohammed Fazl, a "high-risk" detainee alleged to be responsible for the killing of thousands of minority Shiite Muslims between 1998 and 2001.

They also include Noorullah Noori, a former senior military commander; Abdul Haq Wasiq, a former deputy intelligence minister; and Khairullah Khairkhwa, a former interior minister.

Afghan foreign minister will visit Qatar in the "near future" for peace discussions with the Taleban, his spokesman said yesterday.

Zalmay Rassoul will visit Qatar in "the near future on the invitation of the Qatari government", his spokesman Janan Mosazi said.

The minister will hold talks on the relationship between the nations and also "discuss the Afghan peace process," including "the idea of establishing an office... in Qatar to facilitate the peace process," Mosazi said.