Iranian president Ebrahim Raisi. AFP
Washington announced the sanctions late Tuesday, adding to already stringent measures against the Islamic republic.
They came just before talks on reviving a nuclear deal between Tehran and world powers are to resume on Thursday in Vienna, according to Iran's main negotiator.
"Even amid #ViennaTalks, US cannot stop imposing sanctions against Iran," Iranian foreign ministry spokesman Saeed Khatibzadeh tweeted.
"Washington fails to understand that 'maximum failure' and a diplomatic breakthrough are mutually exclusive," he added.
"Doubling down on sanctions won't create leverage -- and is anything but seriousness and goodwill."
The new US measures target government officials and organizations involved in the repression of protesters and political activists and prisons where activists have been held in brutal conditions.
After a pause of several months, the nuclear talks resumed in Vienna last week but paused on Friday.
Ali Bagheri, Tehran's main negotiator, said during a visit to Moscow on Tuesday that the talks would resume Thursday.
A US official, speaking anonymously, said his country was "much less concerned about the when, and much more concerned about... whether Iran comes back to Vienna prepared to engage in good faith".
The Vienna talks are aimed at bringing Washington back into the 2015 deal that offered Iran relief from sanctions in return for curbs on its nuclear activity to ensure it could not develop an atomic weapon.
Former US president Donald Trump pulled out of the deal in 2018.
Iran wants a lifting of all US sanctions which were imposed after Trump's withdrawal.
President Joe Biden's administration, however, has said it will only negotiate measures taken by Trump over the nuclear programme, such as a unilateral ban on oil sales -- not steps imposed on other concerns such as human rights.
Iran has always insisted that its nuclear programme is peaceful.