ABC News chief Washington correspondent Jonathan Karl was on the phone with President Donald Trump just as CENTCOM announced the retaliatory attack against Iran.

"I think it's very important to respond. They shot down a helicopter, and we are responding as we speak," Trump said.

"I believe in responding in a strong manner. I always have throughout my life. And we have a deal that was very good, and probably will [still be]," the president continued. "This is a response to what they did they did with our helicopter last night, and I believe the response should be very strong, very powerful, and that's what this one is."

As the call ended, CENTCOM announced the attack.

U.S. forces have begun launching "self-defense" strikes in response to Iran's attack on a U.S. Army Apache helicopter, U.S. Central Command said.

The strikes began at 5 p.m. ET, it said.

The U.S. Apache attack helicopter that crashed near the coast of Oman overnight was brought down by an Iranian drone, two U.S. officials familiar with the Pentagon’s latest assessment tell ABC News.

The investigation has not yet determined whether Iran intended to use the drone to attack the helicopter, they added.

The drone involved in the incident is the same type Iran typically uses to target ships transiting the Strait of Hormuz, one official said.

-ABC News' Shannon K. Kingston and Luis Martinez

The autonomous surface sea drone used to rescue the two Apache crewmembers picked them up and transported them to another location on the water where they were then hoisted up to a helicopter for further transport, according to a U.S. official.

As President Donald Trump says the U.S. military believes Iran is to blame for the downing of a Apache helicopter that crashed in the Middle East, an Iranian official suggested Iran is ready to retaliate if commitments are broken.

"We prefer the language of diplomacy, but we speak other languages far more fluently. Break your commitments, and we'll switch to what we speak best. You ride the horse you saddled!" the speaker of the Iranian parliament, Mohammad Bagher Ghalibaf, said in a post on X.