Iran launched a new domestically produced missile submarine Sunday amid mounting tensions with the U.S. and Saudi Arabia in the disputed waters of the Persian gulf.

Hassan Rouhani, the president of Iran, introduced the Fateh, or Conquerer, in the southern port city of Bandar Lengeh. Its public revelation is timed to coincide with the country celebrating the 40th anniversary the Islamic Revolution that toppled the former Shah of Iran.

“From this moment, the Fateh Submarine joins Iran’s naval force with my order,” Rouhani said at a ceremony broadcast live on the state-run English-language Press TV.

“Our defence power is solely defensive…Our enemy’s pressure and sanctions imposed on Iran have instigated our progress,” he said.

Ten days ago, Iran’s Revolutionary Guards also unveiled a new ballistic missile with a range of 1,000 kilometers (620 miles).

The surface-to-surface missile — called Dezful — is an upgrade on the older Zolfaghar model that had a range of 700 kilometers, aerospace commander Brigadier General Amirali Hajizadeh said.

The new weapons come two weeks after Iran released a video that shows one of its submarines sinking a U.S. aircraft carrier.

The IRINN news channel aired the clip on February 1, according to a transcription provided by the Middle East Media Research Institute (MEMRI).

The video opens with the aircraft carrier cruising on an open sea escorted by four smaller ships and carrying two planes on its deck. A green periscope bearing an Iranian flag then appears, sinister music begins playing, and one by one, the American ships disappear beneath the surface.

The clip ends with the submarine towing the American ships underwater past a logo reading “40 years,” a reference to the 40th anniversary of the country’s 1979 Islamic Revolution, and a voiceover saying, “Our Iran has the technology to manufacture very advanced Ghadir-class submarines.”