"We're now up over 30 ships (sunk), and in just the last few hours, we hit an Iranian drone carrier ship, roughly the size of a World War II aircraft carrier. And as we speak, it's on fire," Admiral Brad Cooper told a news conference.

Meanwhile, Iranian "ballistic missile attacks have decreased by 90 percent since day one. Drone attacks have decreased by 83 percent since day one," said Cooper, the head of Central Command which is responsible for US forces in the Middle East.

The United States launched a massive air campaign against Iran in concert with Israeli forces on February 28, and Iran has responded by firing waves of attack drones and missiles at other countries in the region.

Destroying Iran's ballistic missile capabilities and its navy are two of Washington's main stated goals for the mission against Iran, which the United States has dubbed "Operation Epic Fury."

Cooper said the United States is not just targeting Iranian missiles, but is also seeking to "level Iran's ballistic missile industrial base."

"As we transition to the next phase of this operation, we will systemically dismantle Iran's missile production capability for the future," the admiral said.