Some of the personnel at the al-Udeid air base in Qatar were asked to leave the base before the end of the day, three diplomatic sources told the news agency.
The call applies to several US bases in the region, according to a senior US official. The source said it was a precautionary measure due to increased tensions.
The move comes at a time when US President Donald Trump has repeatedly threatened US intervention against Iran, in light of the Islamic regime's deadly violence against protesters.
The regime in Tehran, for its part, has warned of Iranian attacks on American military bases in the region if the United States attacks Iran.
Al-Udeid is the largest US base in the Middle East, with around 10,000 troops. The air base in Qatar was attacked by Iran during the 12-day war with Israel in June in response to US attacks on Iranian nuclear facilities.
Prior to the American attacks on Iran, the base had been evacuated and no injuries were reported.
