berlin german chancellor angela merkel tuesday reject total ban arm export nato partner turkey say sales already restrict somewhat turkey remain key ally fight islamic state merkel comment come day foreign minister sigmar gabriel say berlin put arm export turkey hold due deteriorate human right situation country increasingly strain tie merkel tell broadcaster ndr germany would decide arm sales request turkey case-by-case basis also say saw reason impose travel warn germans travel turkey say berlin would keep options open germany 's merkel reject total ban arm export turkey ndr