Al Udeid is the largest US base in the Middle East, housing around 10,000 troops. Ahead of US air strikes on Iran in June, some personnel were moved off US bases in the region.
Earlier in the day, Iran warned regional countries that it will strike US military bases on their soil if Washington attacks Iran, a senior Iranian official told Reuters, after President Donald Trump threatened to intervene amid nationwide anti-government protests.
"Tehran has told regional countries, from Saudi Arabia and the UAE to Turkey, that US bases in those countries will be attacked if the US targets Iran," the official said, adding that Iran had asked those governments to try to prevent any US attack.
Also on Wednesday, Turkey’s foreign minister spoke by phone with his Iranian counterpart and stressed "the need for negotiations to resolve current regional tensions," a Turkish foreign ministry source told Reuters.
Trump said on Tuesday that he has cancelled all meetings with Iranian officials amid the brutal crackdown on protesters, telling Iranians "help is on its way."
"Iranian Patriots, KEEP PROTESTING - TAKE OVER YOUR INSTITUTIONS!!! Save the names of the killers and abusers. They will pay a big price," Trump said in a post on his Truth Social account.
"I have cancelled all meetings with Iranian Officials until the senseless killing of protesters STOPS. HELP IS ON ITS WAY. MIGA [Make Iran Great Again]!!!" he added.