U.S. aims to clinch Afghan deal on prisoner transfer

U.S. Secretary of Defense Chuck Hagel speaks at his news conference at the Pentagon in Washington March 15, 2013.

WASHINGTON (Reuters) - U.S. Defense Secretary Chuck Hagel and Afghan President Hamid Karzai spoke in a call on Saturday about efforts to quickly resolve one of the most vexing issues in the two countries' relations, the delayed transfer to Afghan control of a key detention center.

The Pentagon said the two men "agreed to use the next week to conduct intensive work with a view to concluding an agreement," spokesman George Little said in a statement.

The transfer of the detention center at Bagram air base is a persistent source of tension, with Karzai's office warning in a statement on Wednesday that "any more delays could harm the bilateral relations."

U.S. commanders want to ensure that dangerous prisoners will not be released back to the battlefield. But Karzai has raised alarms by warning that any "innocent" prisoners being held at the facility will be released.

Little's statement said an agreement on the detention facility would be one that both "fully recognizes Afghan sovereignty and our mutual interests in security of the Afghan people and our respective forces."

During Hagel's visit to Afghanistan last weekend, Karzai accused the United States of colluding with the Taliban and of holding unilateral negotiations with the insurgents - allegations the United States sharply denied and which exposed deep tensions after 11 years of war.

The United States plans to pull out just over half of its 66,000 troops from Afghanistan by early next year and leave a relatively small force after 2014, focusing on training Afghan forces and conducting limited counterterrorism operations.

(Reporting by Phil Stewart; Editing by Peter Cooney)