President Trump said Tuesday the Iranians shot down the U.S. military helicopter that crashed in the Middle East late Monday, and he plans to hit back.

Mr. Trump revealed the shoot-down in a social media post, hours after U.S. Central Command said it was investigating the incident.

“I have just been informed by our Great Military that last night the Iranians shot down one of our highly sophisticated Apache Helicopters while patrolling over the Strait of Hormuz,” the president wrote. “There were two pilots involved, both are safe and uninjured. Nevertheless, the United States must, of necessity, respond to this attack.”

The incident comes against the backdrop of a so-called ceasefire between the U.S. and Iran, which is meant to facilitate diplomacy between the two sides in the hopes of ending the war, which began in late February.

However, Iran has been exchanging fire with Israel and is now blamed for the downing of the Army AH-64 Apache helicopter, threatening to upend the fragile talks.

The chopper crashed near the Strait of Hormuz, and its two crew members were rescued, Pentagon officials said.

CENTCOM said the helicopter went down near the coast of Oman while patrolling regional waters. The two crew members are in stable condition, officials said, after being picked up within two hours of the incident.