The U.S. Treasury Department issued new sanctions against Iran Air, Iran's largest air carrier, and Tidewater Middle East Co., a major Iranian port operator owned by Iran's Revolutionary Guard. The Treasury alleged that both firms facilitate illegal shipments in support of international terrorism and nuclear proliferation, and that Iran Air was involved in the transportation of high-tech parts for Iran's advanced missiles and nuclear program. The sanctions restrict U.S. firms from doing business with either entity.