Iran unveiled its new home-grown air defense system on Thursday at a time of increased tensions with the United States.

Iranian officials have previously called Bavar-373 the Islamic republic's first domestically produced long-range missile defense system.

Tehran began making Bavar - which means "believe" - after the purchase of Russia's S-300 system was suspended in 2010 due to international sanctions.

President Hassan Rouhani attended the unveiling ceremony for the mobile surface-to-air system and ordered it to be added to Iran's missile defense network, state news agency IRNA reported.

"The long-range Bavar-373 missile system is suited to Iran's geography with a range of more than 200 kilometers...  and competes with Russian and American systems such as S-300 and Patriot," IRNA said in the report.

The system is "better than S-300 and close to S-400," Rouhani said in televised remarks after the ceremony, held on Iran's "national defense industry day."

Pictures released by his office showed the system mounted on the back of military trucks in Tehran.

Iran installed the S-300 system in March 2016 following several years of delays, after a nuclear agreement reached with world powers the previous year allowed the lifting of international sanctions.

Thursday's unveiling takes place against a backdrop of rising tensions with Washington since US President Donald Trump last year withdrew the United States from the landmark 2015 nuclear deal and reimposed sanctions.