"This kind of aid will only lead to instability and insecurity in the region," foreign ministry spokesman Ramin Mehmanparast told reporters at his weekly press conference.
US Defence Secretary Chuck Hagel, who touted the deal during his trip to Israel, has said it sends Iran a "very clear signal" that military action to stop its controversial nuclear programme is still an option.
The deal will see the Jewish state obtaining anti-radiation missiles designed to take out enemy air defences, radar for fighter jets, aerial refuelling tankers and Osprey V-22 tilt-rotor transport aircraft.
US and Israeli leaders have been at odds over Iran, with President Barack Obama's administration arguing that tough sanctions and diplomacy need to be given more time to work.
But Israel, believed to be the Middle East's sole if undeclared nuclear power, has repeatedly warned time is running out and has refused to rule out a pre-emptive military strike to prevent Iran from obtaining an atomic weapons capability.
In March, Iranian supreme leader Ayatollah Ali Khamenei said his country would "annihilate" the Israeli cities of Tel Aviv and Haifa if the Islamic republic comes under attack from regional arch-foe Israel.
Iran denies it is developing an atomic bomb, saying it is pursuing its nuclear programme purely for peaceful medical and energy purposes.