The US has axed its $500m (£326m) programme to train and equip moderate Syrian rebels to fight Islamic State in another move highlighting western failures as Russia seizes the initiative by launching direct military intervention in support of Bashar al-Assad.
Pentagon officials were expected to officially announce the end of the programme on Friday as the US defence secretary Ashton Carter left London after meetings with his British counterpart Michael Fallon about the conflicts in Syria and Iraq, the New York Times reported.
The programme was the most visible element of US backing for Syrian opposition groups but it has already suffered embarrassing setbacks.
Last month it transpired that it had trained only four or five fighters inside Syria and that others had surrendered to rival groups and handed over the their weapons when they crossed the border from Turkey.
Other covert programmes are run by the CIA.