President Joe Biden said Friday that the United States would support Iranians a year after the death of Mahsa Amini sparked mass protests, as Washington unveiled fresh sanctions against "egregious" rights abusers.

Biden said in a statement that "today -- as we remember Mahsa's tragic death -- we reaffirm our commitment to the courageous people of Iran who are carrying on her mission."

"Iranians alone will determine the fate of their country, but, the United States remains committed to standing with them -- including providing tools to support Iranians' ability to advocate for their own future," Biden added.

Biden said the United States was "announcing additional sanctions targeting some of Iran's most egregious human rights abusers" to mark the anniversary.

Amini, a 22-year-old Iranian Kurd, died on September 16 last year after her arrest in Tehran for an alleged breach of the Islamic republic's strict dress code for women.

Her death triggered months of nationwide demonstrations under the slogan "Woman, Life, Freedom".

The US Treasury Department said it had added 25 Iranian officials, three media outlets and a research firm onto their sanctions blacklist, saying all were linked to Tehran's suppression of protests after Amini's death.

Most were regional commanders of the national police force and the Islamic Revolutionary Guard Corps.

Also sanctioned was Gholamali Mohammadi, the head of Iran's Prisons Organization, who the Treasury said presides over serious human rights abuses including torture and rape.

Three state-controlled media groups, Press TV, Tasnim News and Fars News were also placed on the blacklist.

The "internet research firm" refers to a company that helps the government police and censor the internet.

The Treasury said they "work in tandem with Iranian security and intelligence services ... extending the regime's oppressive reach."

US Secretary of State Antony Blinken said Washington's sanctions were in coordination with the United Kingdom, Canada, Australia "and other partners who are also imposing sanctions this week".

London announced fresh sanctions against Iran earlier Friday.

The sanctions come after the US and Iran reached a deal to release five detained US citizens in exchange for the unfreezing of $6 billion of Iranian funds.

The US citizens are expected to be released next week.