The Iranian Foreign Ministry announced that delivery of the Russian S-300 air defense system to Tehran is underway, Iran’s semi-official state news agency Fars reported on Monday.

During his weekly press conference, Foreign Ministry Sp0kesman Hossein Jaberi Ansari noted that the delivery process was in its final stages and had been progressing according to a schedule agreed to by both Tehran and Moscow.

Ansari’s remarks echoed a statement made earlier this month by Iranian Defense Minister Brigadier General Hossein Dehqan, according to which the S-300 would be transferred to Tehran by the end of the Iranian calendar year, or March 20, 2016.

The Russian-made S-300 surface-to-air missile system is considered to be one of the most advanced in the world. It is capable of intercepting and shooting down multiple aircraft and long-range cruise and ballistic missiles.