A U.S. Marine Corps Osprey aircraft with 26 passengers on board crashed off the eastern coast of Australia on Saturday.

The Marine Corps confirmed the incident, stating that an active search-and-rescue mission is underway to recover missing servicemembers after what the military called a "mishap."

The Marines Corps said that 23 passengers have been recovered from the aircraft, and that there are three servicemen missing.

President Trump, who is starting his August vacation in New Jersey this weekend, has been briefed on the matter by chief of staff John Kelly, a White House press pool report said Saturday afternoon.

The MV-22 Osprey is a vertical take-off and landing aircraft with rotating propellers that enable it to both fly like a helicopter and a fixed wing aircraft.

The aircraft had a lot of ups-and-downs in early development more than a decade ago. But once perfected, it has become a fixture in the U.S. military's arsenal as a troop support aircraft primarily used to move personnel and equipment onto the battlefield.