The United States vowed Saturday to immediately investigate a NATO cross-border air attack that reportedly killed 24 Pakistani troops and enraged the Pakistani government.

In a joint statement, State and Defense Secretaries Hillary Clinton and Leon Panetta offered their "deepest condolences for the loss of life," while voicing full support for "NATO's intention to investigate immediately."

Clinton, Martin Dempsey, chairman of the U.S. Joint Chiefs of Staff, and John Allen, commander of the NATO-led coalition forces in Afghanistan, each called their Pakistani counterparts after the fatal attack, the joint statement said. The statement added that U.S. Ambassador to Pakistan Cameron Munter also held emergency meetings with Pakistani officials in Islamabad.

According to the statement, when contacting their Pakistani counterparts, the U.S. diplomatic and military leaders each stressed the importance of the U.S.- Pakistani partnership, which serves the mutual interests of their peoples. Also, they said they would remain in close contact with their Pakistani counterparts in dealing with the ongoing challenges.

Thirteen other Pakistani troops were also reportedly injured in the incident that occurred in the tribal region of Mohmand Agency, which borders Afghanistan.

After an emergency meeting of the Defense Committee, chaired by Prime Minister Syed Yousuf Raza Gilani Saturday night, the Pakistani government decided to close NATO's logistics supply lines. Pakistan also asked the U.S. to vacate Shamsi Air Base in southwestern Balochistan province within 15 days in an apparent protest against NATO strikes.