Iran's army is now equipped with a Russian air defence system after a long and controversial delivery process, Defence Minister General Hossein Dehghan was quoted as saying Tuesday.
"I inform our people that... we are in possession of the strategic S-300 system" and that it "serves our air force's counterattack command," Dehghan said, according to ISNA news agency.
Parts of the system, including missile tubes and radar equipment, were displayed on April 17 during a military parade in southern Tehran.
The United States and Israel have criticised Russia for the sale of the S-300 system to the Islamic republic.
Tehran says it is needed to strengthen its air defence against possible attacks, including on its nuclear facilities.
Iran and Russia originally signed a contract for its delivery in 2007, but in 2010 Moscow suspended the sale after the UN Security Council issued a resolution against Iran's nuclear programme.
In 2015, shortly before the conclusion of an international agreement on Tehran's nuclear programme, Moscow re-authorised the delivery.
The two countries are also in talks for delivery to Iran of Sukhoi SU-30 fighter jets, a deal also criticised by Washington.
Dehghan also announced that Iran will start manufacturing this year an air defence system, Bavar 373, "capable of destroying cruise missiles, drones, combat aircraft and ballistic missiles."
"This long-range system is able to destroy several targets at once," he added.