Radical students cemented the Islamic Revolution by storming the embassy soon after the fall of the U.S.-backed Shah, and 52 Americans were held hostage there for 444 days.
The two countries have been enemies ever since and, as Iranian authorities on Friday urged security forces to swiftly stamp out anti-government protests that have spread to all layers of society, new bilateral tensions surfaced.
Iranian President Ebrahim Raisi criticised Joe Biden, a day after the U.S. president vowed to “free Iran”.
Images broadcast on state television showed anti-American demonstrations attended by tens of thousands of people across the country on the “National Day of Fighting Global Arrogance”, while songs called for “Death to America” and described Iran’s arch-foe as a manifestation of Satan.
Schoolchildren carried banners in support of the storming of the embassy and waved Iranian flags.
Friday’s pro-establishment demonstrations offered a stark contrast to the wave of protests that has swept the country since a 22-year-old Kurdish woman, Mahsa Amini, died in morality police custody on Sept. 16 after being arrested for being inappropriately dressed.
The protests present one of the biggest challenges to the authority of the leadership enshrined by the 1979 Islamic Revolution, with many young Iranians overcoming the fear that has stifled dissent ever since.
Iran has blamed the United States and other foreign enemies for the unrest, saying they want to destabilise the country.
Biden said on Thursday that the demonstrators would soon succeed in freeing themselves.
“Don’t worry, we’re gonna free Iran. They’re gonna free themselves pretty soon,” Biden said during a campaign speech in California, as dozens of demonstrators gathered outside holding banners supporting the Iranian protesters.
Biden did not expand on his remarks.
Raisi called the protesters “deceived traitors”, adding: “I am telling Biden that Iran was freed 43 years ago.”
Raisi’s deputy, Mohammad Hosseini, called on security forces to “work swiftly to end the riots”.
Women, who have been burning their veils, and university students are playing a prominent role in the demonstrations, which call for the death of Supreme Leader Ayatollah Ali Khamenei, but they have attracted support from a broad cross-section of society.
The activist HRANA news agency said on Friday that 300 protesters had been killed in the unrest as of Thursday including 47 minors, as well as 37 members of the security forces.
More than 14,000 people have been arrested, including 385 students, in protests in 134 cities and towns, and 132 universities, it said.