For the third straight year since 2015, Iran has revealed the existence of another underground ballistic missile production factory buried so deep as to be unassailable by the U.S. Air Force.

This third underground factory, like two others revealed in 2015 and 2016, will build ballistic missiles and develop new ones.

"Iran's third underground factory has been built by the Guards in recent years ... We will continue to further develop our missile capabilities forcefully," said Brig. Gen. Amir Ali Hajizadeh, commander of Aerospace Force of the Army of the Guardians of the Islamic Revolution.

Iran claims it has hundreds of these underground bases throughout the country.

In October 2015, Iranian state-controlled media published photos and videos of a missile facility it claims is buried an astounding 500 meters underground in an unspecified mountain range.

"This is a sample of our massive missile bases," said Gen. Hajizadeh at the time.

"Our power and capabilities are like an iceberg that floats above water and whose tip barely shows above the clear water."

He also noted Iran's "long-range missile bases are stationed and ready under the high mountains in all the country's provinces and cities."

In January 2016, Iran disclosed a second underground missile base housing Emad liquid-fuel, medium-range ballistic missile (MRBM) with a claimed range of 1,700 km and 750 kg payload.

The U.S. claimed Emad can carry a nuclear warhead and thus violates a 2010 UN Security Council resolution. On the other hand, Iran says its missile program is not in defiance of a U.N. resolution that calls on it to desist from working on ballistic missiles designed to deliver nuclear weapons for up to eight years.

"It is natural that our enemies America and the Zionist regime (Israel) are angry with our missile program because they want Iran to be in a weak position," said Gen. Hajizadeh.