Two C-130 aircraft were lost during the operation, an official said.
President Donald Trump announced "major combat operations" against Iran on Feb. 28, with massive joint U.S.-Israeli strikes attack targeting military and government sites, officials said.
Watch special coverage on Nightline, "War with Iran," each night on ABC and streaming on Disney+ and Hulu.
Both the United Arab Emirates and Saudi Arabia reported fresh Iranian attacks on Thursday morning.
The UAE's Defense Ministry said in a post to X that its air defenses were "engaging with missile and drone attacks originating from Iran."
The Saudi Defense Ministry reported the downing of at least five drones and one ballistic missile since midnight on Wednesday.
The U.S Embassy in Baghdad on Thursday urged all American citizens to leave Iraq immediately citing the danger that "Iran-aligned Iraqi terrorist militias may intend to carry out attacks in central Baghdad within the next 24 to 48 hours."
The embassy alert said that Iran and its allied Iraqi groups have carried out "widespread attacks against U.S. citizens and U.S.-associated targets throughout Iraq, including in the Iraqi Kurdistan region."
"Terrorist militias have targeted Americans for kidnapping, and U.S. citizens should leave Iraq immediately," the alert said. "The government of Iraq has not been able to prevent terrorist attacks that occur within Iraqi territory or launch from it."
The warning follows the kidnapping of American journalist Shelly Kittleson in Baghdad earlier this week.
President Donald Trump said that the U.S. is going to hit Iran "extremely hard" over the next two weeks.
He then followed that by saying discussions with Tehran are ongoing.
Trump's nearly 20-minute White House address reiterated much of what the president has been saying since the strikes began, with little new light shed on the operation or a specific timeline for when the war would end.
Regarding the trade disruptions from the effective blockade of the Strait of Hormuz, President Donald Trump said he has two suggestions to impacted countries: buy oil from the U.S., and "build up some delayed courage" and "protect" the passageway themselves.
"Iran has been essentially decimated. The hard part is done, so it should be easy," he said in his address.
"And in any event, when this conflict is over, the strait will open up naturally, it'll just open up naturally," he claimed.
