John Kerry in Afghanistan on heels of President Karzai's U.S.-bashing

KABUL U.S. Secretary of State John Kerry has flown into Afghanistan on an unannounced visit to see President Hamid Karzai amid concerns the Afghan president may be jeopardizing progress in the war against extremism with anti-American rhetoric.

Kerry arrived in the Afghan capital on Monday for a 24-hour visit and was to meet Karzai, civic leaders and others to discuss continued U.S. assistance to the country. His visit coincides with the handover of a major detention center to Afghan officials.

It also comes as Karzai has infuriated U.S. officials by accusing Washington of colluding with Taliban insurgents to keep Afghanistan weak even as the Obama administration presses ahead with plans to hand off security responsibility to Afghan forces and end NATO's combat mission by the end of next year.

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CBS News correspondent Margaret Brennan reports that Kerry met Sunday night with a top Pakistani general, with whom he discussed how Pakistan can help ease the U.S. transition to Afghan security forces.

Karzai irked Washington in early March with a suggestion that U.S. troops had acted in concert with Taliban militants to keep his own leadership weak -- a charge flatly denied by Secretary of Defense Chuck Hagel, who happened to be visiting Afghanistan when it was made.

The U.S. military gave control of its last detention facility in Afghanistan to Kabul, meanwhile, a year after the two sides initially agreed on the transfer.

The Monday handover of Parwan Detention Facility ends a bitter chapter in American relations with Afghanistan's mercurial president Karzai, who demanded control of the prison as a matter of national sovereignty.

The dispute threw a pall over the ongoing negotiations for a bilateral security agreement that would govern the presence of U.S. forces in Afghanistan after 2014.

Top U.S. commander in Afghanistan Gen. Joseph Dunford handed over Parwan, located near the U.S.-run Bagram military base north of Kabul, at a ceremony there after signing an agreement with Afghan Defense Minister Bismullah Khan Mohammadi.

"The transfer of the detention facility is an important part of the overall transition of security lead to Afghan National Security Forces. This ceremony highlights an increasingly confident, capable, and sovereign Afghanistan," Dunford said.

An initial agreement to hand over Parwan was signed a year ago, but efforts to follow through on it constantly stumbled over American concerns that the Afghan government would release prisoners that it considered dangerous.

A key hurdle was a ruling by an Afghan judicial panel holding that administrative detention, the practice of holding someone without formal charges, violated the country's laws. The U.S. argued that international law allowed administrative detentions and also argued that it could not risk the passage of some high-value detainees to the notoriously corrupt Afghan court system.

An initial deadline for the full handover passed last September and another earlier this month.

The formula for how the two sides resolved this dilemma has not been made public. Officials say that the Afghan government will be able to invoke a procedure that ensures prisoners considered dangerous will not be released from the detention center. According to a senior U.S. official in Washington, the agreement also includes a provision that allows the U.S. and Kabul to work together to resolve any differences. The official lacked authorization to discuss the details of the agreement publicly and spoke on condition of anonymity.

The detention center houses about 3,000 prisoners and the majority are already under Afghan control. The United States had not handed over about 100, and some of those under American authority do not have the right to a trial because the U.S. considers them part of an ongoing conflict.

There are also about three dozen non-Afghan detainees, including Pakistanis and other nationals that will remain in American hands. The exact number and nationality of those detainees has never been made public.

A new agreement, or memorandum of understanding, was signed at the ceremony by Dunford and Khan, but the U.S. military said it will not be made public. The agreement supplants one signed last March, which had been made public.

The U.S. military said in a statement that the new agreement "affirms their mutual commitment to the lawful and humane treatment of detainees and their intention to protect the people of Afghanistan and coalition forces," an apparent reference to the release of detainees deemed to be dangerous.

The handover should also open the way for a resumption of talks for a bilateral security agreement that would govern the presence of U.S. forces in Afghanistan after 2014.

It is part of an ongoing effort to gradually shift control of the country's security to the Afghans as the U.S. and allies move toward the full withdrawal of combat troops by the end of 2014.

There are about 100,000 coalition troops in Afghanistan, including about 66,000 from the United States. American officials have made no final decision on how many troops might remain in Afghanistan after 2014, although they have said as many as many as 12,000 U.S. and coalition forces could remain.