Iran's Foreign Ministry spokesman Hossein Jaberi-Ansari expressed sympathy with the Turkish government and nation and offered condolences to the families of the victims.
The car bomb blast occurred near the armed forces' headquarters in central Ankara on Wednesday.
Jaberi-Ansari said the incident once again underscored the need to fight terrorism as a global threat.
Russia on Thursday expressed its deep condolences to the people of Turkey over the deadly explosion in Ankara, Russia's Foreign Ministry said.
It said the terrorist act underlined the need for all countries to unite to fight international terrorism.
Following the incident, Turkish President Recep Tayyip Erdogan vowed revenge against those responsible for the blast.