U.S. President Donald Trump said on Thursday that Iran made a big mistake after it said it had shot down an American drone.

Axar.az reports citingt Anadolu Agency.

"Iran made a very big mistake!" Trump tweeted.

Earlier on Thursday, Tehran announced that it shot down a U.S. military drone.

An American official confirmed to ABC News that the U.S. Navy MQ-4C Triton, a high altitude unmanned aerial vehicle used for surveillance, was shot down by an Iranian surface-to-air missile while the drone was flying in international airspace over the Strait of Hormuz.

The confirmation comes amid growing hostility in the Gulf region between Washington and Tehran.

Tensions have been rising between the U.S. and Iran since last year, when Washington unilaterally withdrew from a landmark 2015 nuclear deal between Tehran and the five permanent members of the UN Security Council plus Germany.