Brigadier General Abbas Nilforoushan was killed in Israeli strikes on Beirut on Friday, in which Hezbollah's leader Sayyed Hassan Nasrallah also died.
Israel's intensified attacks against the Hezbollah militia in Lebanon and the Houthi militia in Yemen have prompted fears that Middle East fighting could spin out of control and draw in Iran and the United States, Israel's main ally.
"We stand strongly and we will act in a way that is regretful [for the enemy]" Kanaani told a weekly news conference, adding that Iran does not seek war but is not afraid of it.
Kanaani said that Iran is closely following up on matters with the Lebanese authorities, referring to the strikes that killed Nasrallah and Nilforoushan.
