"There is no room for complacency. There are risks of failing in Afghanistan. We cannot afford to fail. If we fail we will see an increase, an increase in drugs, and dangerous instability in this region."
Cameron praised the work of British troops but said other Nato countries need to take on a greater share of the burden
"Britain is definitely bearing its share of the burden. We need more helicopters, we need more support and we need other Nato countries to play their part,"
Calling for a "hard-headed assessment" of the situation he said that changes are needed in the way the international community was operating, including a single individual to co-ordinate the civilian reconstruction effort and better co-ordination between Nato military forces.He said:
"To make sure that we succeed, we have to take tough, gritty, hard-headed decisions about making sure that there is a greater unity of purpose about what we are doing here.