The US Navy is leading its largest-ever war games in the Persian Gulf, with warships from 25 countries being deployed in the region.

Tehran, in return, is preparing for its biggest air defense war game in the history of Islamic Republic next month.

The US, Britain, France, Saudi Arabia and the UAE have deployed the largest number of warships for the 12-day training mission.

The exact number of aircraft carriers, battleships and submarines taking part is unclear. Three American aircraft carriers out of the four currently in commission are reportedly gathering in the Persian Gulf for the training. USS Enterprise, USS John C. Stennis, USS Dwight D. Eisenhower have reportedly arrived.

The aircraft carriers are supported by at least a dozen warships: Ballistic missile cruisers, destroyers, frigates and assault ships carrying thousand of US Marines and spec ops ships.

Britain dispatched six vessels to the Persian Gulf war games: the HMS Diamond, a brand-new £1 billion worth destroyer, four minesweepers and a logistics vessel.

The joint fleet is expected to simulate destroying Iranian fighter jets, battleships and coastal military defenses like missile batteries.