NEW : An attacker in an Afghan police uniform killed a NATO service member Sunday , Defense says . 3 ISAF troops were killed Saturday in an IED attack . Kandahar province Secretary of Defense Leon Panetta called Afghan President Leon Panetta on Sunday . The attacks come at a critical time for the United States , which has picked up the pace of training Afghan forces as it prepares to withdraw troops by the end of 2014 . NATO says an airstrike has killed a senior Taliban leader .
NEW : An attacker in an Afghan police uniform killed a NATO service member Sunday , Defense says . 3 ISAF troops were killed Saturday in an IED attack . Kandahar province Secretary of Defense Leon Panetta called Afghan President Leon Panetta on Sunday . NATO says an airstrike has killed a senior Taliban leader .