Washington, Jan 6 - The US has halted the transfer of inmates from the Guantanamo Bay detention facility back to Yemen, where an Al Qaeda branch allegedly plotted the Dec 25 attack on a Detroit-bound airliner, President Barack Obama said Tuesday.

About half of the nearly 200 remaining prisoners at Guantanamo are Yemeni citizens, making their fate a key component of the administration's pledge to close the controversial facility in Cuba.

Obama said the administration still intends to close Guantanamo. But the "unsettled situation" in Yemen, which is battling the terrorist group Al-Qaeda, had forced the transfers to be stopped.

"Make no mistake. We will close Guantanamo prison, which has damaged our national security interests and become a tremendous recruiting tool for Al-Qaeda," Obama said.

Umar Farouk Abdulmutallab, the 23-year-old Nigerian charged with attempting to blow up the Christmas Day flight from Amsterdam to Detroit, was reportedly trained and acquired his explosives in Yemen.

The White House has been under pressure since reports emerged that two former Guantanamo detainees have become major figures in the Yemeni-based terrorist group Al-Qaeda in the Arabian Peninsula, which has claimed responsibility for the Detroit attack.

Obama originally promised a year ago to close Guantanamo by Jan 22, but has since acknowledged that his deadline will not be met. (dpa)