The State Department said Tuesday the new policy would allow foreign governments that meet certain requirements — and pledge not to use the unmanned aircraft illegally — to buy the vehicles that have played a critical but controversial role in combating terrorism and are increasingly used for other purposes. Recipient countries would be required to sign end-use statements certifying that the drones would not be used for unlawful surveillance or force against domestic populations and would only be used in internationally sanctioned military operations, such as self-defense.

Each sale would be reviewed individually and the pledges would be monitored for compliance, the department said in a statement.

Previously, drone transfers had been governed by regulations that presumed that requests would be denied except in highly unusual circumstances. Certain armed drones — those with a range of 186 miles (300 kilometers) and able to carry a payload of 1,100 pounds (500 kilograms) — will still be subject to those restrictions.