WASHINGTON — The Obama administration on Tuesday issued new rules for the international export of armed drones, a move that seeks to preserve an American lead in a fast-growing market but one likely to speed the proliferation of a much-criticized weapon in the battle against terrorism.

The rules will make it easier to provide missile-armed Predator and Reaper drones to American allies facing off against militant groups, including the Islamic State and its offshoots, aviation experts said. The long-awaited policy shift will reduce the chance that friendly countries will turn for drones to Israel or China, which also manufacture unmanned military aircraft for export.

The State Department said the new policy set strict standards for the sale of armed drones, including “end-use assurances” from the recipient countries that set out how they can be used. For drones capable of carrying large weapons, there will be a “strong presumption of denial” of an export license. But exceptions will be allowed on “rare occasions,” the department said, citing language that also governs other weapons exports.

The export rules will not permit buyers to use American drones “to conduct unlawful surveillance or use unlawful force against their domestic populations,” the State Department said.