Period . NEW : Pakistan 's prime minister says he wants good relations with the United States . The U.S. is vacating Shamsi Air Base , which is used by unmanned combat aircraft . The cost of vacating the air base is likely to be minimal , experts say . Pakistan asked the US to leave the base after an airstrike killed two Pakistani troops .
NEW : Pakistan 's prime minister says he wants good relations with the United States . The U.S. is vacating Shamsi Air Base , which is used by unmanned combat aircraft . The cost of vacating the air base is likely to be minimal , experts say . Pakistan asked the US to leave the base after an airstrike killed two Pakistani troops .