moscow russia accuse unite state wednesday allow islamic state operate nose syria say washington let militant group move freely area abut u.s. military base allegations make russia defense ministry center u.s. military base tanf strategic syrian highway border cross iraq south country russia say u.s. base illegal area around become black hole militants operate unhindered unite state say tanf facility temporary base use train partner force fight islamic state pentagon spokesman colonel robert man tuesday say washington remain commit kill islamic state deny safe havens ability carry strike major-general igor konashenkov spokesman russian defense ministry say moscow want know around 300 islamic state militants pickup truck pass u.s.-controlled area try block highway damascus deir al-zor use supply syrian force say u.s. yet give explanation suggest american side also explain another incidence selective blindness towards militants operate nose konashenkov say statement say 600 militants base refugee camp u.s. control area drive en masse former customs post call tafas syrian-jordanian border early month seize food medical supply mean locals need expert forecast attempt rupture peace agreement southern de-escalation zone say konashenkov issue warn responsibility sabotage peace process lay exclusively american side russia say islamic state operate near u.s base syria unhindered