U.S. President Barack Obama has expressed "deep concern" about the recent killings of NATO troops in Afghanistan by their allies among the Afghan security forces.
Obama said he would reach out to Afghan President Hamid Karzai about the development.
His remarks came after the chairman of the U.S. Joint Chiefs of Staff, General Martin Dempsey, met in Kabul on August 20 with Afghan military leaders.
Dempsey said his Afghan counterparts are "for the first time" as concerned as Washington about insider attacks.
Ten soldiers, mostly from the United States, have been killed by Afghan troops during the past two weeks.
NATO's130,000 troops in Afghanistan are due to withdraw by the end of 2014.
Dempsey said insider attacks will not alter the withdrawal timetable.
Based on reporting by Reuters, AP, and AFP