The U.S. is poised to admit significant responsibility for an attack on the Pakistan-Afghanistan border last month that left 24 Pakistani solders dead. A military investigation found U.S. and Afghan commandos incorrectly determined there were no Pakistani forces in the area before the air strike. U.S. officials then provided inaccurate data to a Pakistani military representative and missed an opportunity to stop the fighting. Pakistan closed its border after the attack, shutting off a supply line to troops in Afghanistan.