U.S. military strikes against Iran on the second night in a row have been completed, U.S. Central Command said.

In a statement, CENTCOM said U.S. forces "completed additional self-defense strikes against multiple targets," including against Iranian military surveillance capabilities, communication systems and air defense sites.

The statement went on to say: "U.S. Marine Corps, Air Force, and Navy assets fired precision munitions on Iranian targets that posed a threat to U.S. forces and international commercial ships transiting regional waters. The strikes are in response to Iran's unwarranted and continued aggression. U.S. forces remain vigilant, lethal, and ready."

U.S. Central Command is denying Iran's claim that the Strait of Hormuz is closed, saying that commercial ships continue to transit in and out of the waterway.

Iran vowed to "give a crushing and decisive response" to the U.S. strikes, according to Iran's Fars News Agency state media.

The Islamic Revolutionary Guard Corps claimed it has completely closed the Strait of Hormuz due to U.S. strikes in Iran.

The IRGC said the strait is "declared closed to all vessels, including oil tankers and commercial ships, due to security concerns, and any passage will be targeted," according to a statement published by state media.

The strait is closed until further notice, the IRGC Navy said while alleging the U.S. has repeatedly violated the ceasefire.

President Donald Trump appeared to confirm that a U.S. Army ‌helicopter went down near the Strait of Hormuz, which was reported by The New York Times late on Monday.

Trump claimed that the pilots were not injured and that a report on the incident will be released on Tuesday.

"The pilots are fine," the president said. "Nobody injured. We are going to issue a report tomorrow, but the pilots are fine," Trump added, when asked about an update on the crash during a gaggle on the tarmac in New York following Game 3 of the NBA finals.

-ABC News' Isabella Murray