The Obama administration has imposed travel bans on more than 50 senior Iranian officials accused of participating in human rights abuses and political repression.
The State Department announced on Friday that it, along with Britain, had hit 52 Iranian government ministers, military leaders and law enforcement, judicial and prison officers with visa restrictions that will bar them from entering the United States. Canada is expected to take similar action soon.
"Today's actions are an important reminder to Iran that the international community will continue to hold accountable those officials who commit human rights abuses and suppress the democratic aspirations of fellow citizens," Secretary of State Hillary Rodham Clinton said in a statement.
The Obama administration has been raising pressure on Iran over concerns that it is repressing pro-democracy advocates and abusing the rights of students, religious and ethnic minorities, women's rights leaders and other groups.
The State Department would not divulge the names of those affected by Friday's travel bans, citing the confidentiality of visa records.
The step was taken under a law that allows the secretary of state to revoke or deny visas for foreigners whose presence in the United States would have negative foreign policy consequences. Similar penalties have been imposed on officials from Libya, Belarus and the Ivory Coast.
There are also separate international sanctions on Iran related to its uraninum enrichment program, which the U.S. and its allies say is aimed at producing nuclear weapons, a claim Iran denies.