The incident occurred with the carrier about 500 miles (800 kilometers) from Iran's coast, and came on the same day that American forces responded to Iranian boats that threatened to board a US-flagged tanker in the Strait of Hormuz.

"An F-35C fighter jet from Abraham Lincoln shot down the Iranian drone in self-defense and to protect the aircraft carrier and personnel on board," US Central Command spokesman Captain Tim Hawkins said in a statement.

The shootdown took place after the Shahed-139 drone "continued to fly toward the ship despite de-escalatory measures taken by US forces," Hawkins said.

He also confirmed a separate incident that occurred later Tuesday in which two Iranian boats and a drone approached the US-flagged ship M/V Stena Imperative "at high speeds and threatened to board and seize the tanker."

An American destroyer -- the USS McFaul -- responded with support from the US Air Force and escorted the tanker, which is now "proceeding safely," Hawkins added.

US President Donald Trump has threatened military action against Iran and sent a flotilla of warships to the Middle East following anti-government protests in Iran that were met with a deadly crackdown last month.

Trump has said he is hopeful Washington will "work something out" with Tehran, but also warned that "bad things would happen" if a deal was not reached, while Iran insists it wants diplomacy while promising a decisive response to any aggression.