The head of the US Joint Chiefs of Staff is in Afghanistan for talks with senior commanders on 'insider attacks' amid a spate by Afghan soldiers on NATO troops.
General Martin Dempsey said on Sunday that efforts have been made to improve the screening of recruits and to pre-empt potential turncoat attacks, but the number of incidents continue to increase.
"We have an eight-step vetting process that's been in place in earnest for about a year. But we haven't turned the corner on the trend," he said.
General Dempsey suggested the Afghan government could be doing more to thwart the insider attacks, including speaking out publicly.
The death toll this year from 'insider attacks' is 40.