"Although US armed drones are made by private firms such as Northrop Grumman and General Atomics, sales would be made through government-to-government negotations. Mr Williams said strict US State Department rules on who could buy armed drones meant the new market would not be a free-for-all. New customers will have to satisfy the US they will comply with international humanitarian and human rights laws. Countries applying to buy drones would be subjected to a "strong presumption of denial", meaning that they would have to make a strong case for needing the weapons. Successful countries will need to prove that their applications constitute the "rare occasions" set out in a 1987 treaty signed by the G7 - Canada, France, Germany, Italy, Japan, the United Kingdom, and the United States - known as the Missile Technology Control Regime. This includes assurances they will only use the weapons for the stated purposes, will not modify them without America's consent, and will not transfer the weapons (or replicas of them) elsewhere."