The European Union was to add around 30 senior Iranian officials and government bodies to its sanctions blacklist on Monday, in response to a hardening crackdown on protests rocking the country.
Foreign ministers from the bloc were meeting in Brussels and expected to sign off on the move -- shortly after Tehran issued its first death sentences over the demonstrations.
"Today we are going to approve another package of sanctions against the people responsible for the repression of the demonstrators," EU foreign policy chief Josep Borrell said.
Last month the bloc hit Iran's "morality" police, revolutionary guard and IT minister with asset freezes and visa bans, citing attempts to crush protests over the death of Mahsa Amini.
Tehran has warned of a "proportionate and firm" response to the EU over the expanded sanctions.
Ministers were also set to discuss Iran's delivery to Russia of kamikaze drones that have been used to strike civilian energy infrastructure in Ukraine.
The bloc has already also slapped asset freezes and visa bans on Iran's drone maker and three top military officials over the supplies.
But some member states are pushing for the EU to broaden the punitive measures over the weapons.
A senior EU official said the bloc was probing reports over the possible delivery of ballistic missiles by Iran to Russia and would sanction Tehran further if it sent the arms.
Borrell said so far that Brussels had "no evidence" over the supplies of ballistic missiles.
Brussels has faced a tricky balancing act over its response to Tehran as the EU is mediating a push to revive the 2015 Iran nuclear deal.
Those efforts to get Iran and the United States back onboard with the agreement have largely stalled.
"It is not in a good track, you know, stalemate, but the work continues," Borrell said.