Iran on Saturday denounced US tech giant Meta's decision to remove the Facebook and Instagram accounts of its supreme leader Ayatollah Ali Khamenei, calling it a "violation of freedom of expression".

Instagram and Facebook are among the most popular social media platforms for Iranians, but while the government blocks their use, officials in the Islamic republic have accounts on them.

Meta said last month it had removed Khamenei's accounts from Facebook and Instagram for having "repeatedly violated" its policy on "dangerous organisations and individuals".

In response, Iranian Foreign Minister Hossein Amir-Abdollahian said the move was "not only a violation of freedom of speech, but also an insult to millions of followers of his positions and news".

"The mottos of freedom of expression by some Western claimants are hollow and showy slogans and a cover for their illegitimate political goals," he told the Middle East Eye news outlet in remarks also published by Iran's foreign ministry.

Khamenei, 84, has been the country's supreme leader since 1989, a position that allows him the final say in major state policies. He had about five million followers on Instagram.

Meta's move on February 8 came as Khamenei increasingly voiced support for Palestinian militant group Hamas and denounced Israel amid the war between the two sides in the Gaza Strip.

"Khamenei is the most prominent supporter of the oppressed people of Palestine and Gaza in the world, and the Silicon Valley Empire cannot prevent this voice from reaching the public opinion of the world," Amir-Abdollahian said.

Despite the Iranian government's ban on Facebook, Instagram and other social media platforms including X, internet users in the Islamic republic can still access them using virtual private networks, or VPNs.