The US has said the release of footage showing a captured soldier in Afghanistan violates international law.In the video, private Bowe Bergdahl calls for the withdrawal of foreign forces from Afghanistan. His military superiors have described it as Taliban ‘propaganda’. ‘‘Well, they are demanding that we stop searching for the soldier and basically they would like us to go home. That is just simply not going to happen. We are here to support the Afghan government to improve security and we will stay as long as the Afghan people want us here,’‘ said US military spokesman Colonel Greg Julian. The video release came hours before a helicopter crashed at NATO’s Kandahar base. A total of 16 civilians were killed and five injured. The crash is the second involving a former Soviet helicopter in less than a week, as NATO forces continue their intensified offensive against the Taliban in the south of the country.