U.S. Senator John McCain says he hopes a strategic partnership agreement with Afghanistan can be finalized before a NATO meeting in May, but that the United States will not resolve sensitive issues in a way that might put American service members at risk.

McCain led a group of five senators for talks Sunday in Kabul with Afghan President Hamid Karzai.

The president's office said Mr. Karzai pushed for the transfer of Bagram prison to Afghan control, and stressed the need for an end to night raids by international troops. He said the issues are of “grave importance” to the Afghan people.

But McCain says carrying out the raids at night is important for troop safety.

“So we emphasized to President Karzai that we believe that this issue can be resolved, but we are strongly opposed to any termination of night raids because of the added risk it would put on the men and women in our military, which obviously is not something that we would ever agree to.''

McCain also said successful peace talks with the Taliban will be more difficult because of the planned pullout of international troops by the end of 2014.