An Iraqi official told The Associated Press on Saturday that Baghdad was informed about the waiver during a call the previous day between U.S. Secretary of State Mike Pompeo and Iraqi Prime Minister Adel Abdul-Mahdi.
Another official confirmed the waiver, saying it will start June 19.
Both officials spoke on condition of anonymity as they were not authorized to speak to the media.
Iraq's power sector is in disrepair and doesn't generate enough electricity to meet domestic demand, especially during the scorching summer months.
Iraq has received one waiver after another since U.S. sanctions on Iran went into effect in November.