The United States has created a Twitter account in Farsi to communicate with social media users in Iran as Iranian opposition websites renewed calls for a rally on Monday.
"The US State Department recognizes the historic role of social media among Iranians in the world now. We want to join in your conversations," the State Department said on Sunday in the initial tweet on its new USAdarFarsi Twitter account.
The Twitter account is the latest channel the US government has opened for relaying its message to Iranians. Voice of America broadcasts Farsi news and other programs daily on radio, television and the Internet.
Iranian leaders accuse the US government-funded Voice of America of trying to undermine the Islamic Republic via the broadcasts.
Subsequent State Department tweets criticized the government of Iran for not allowing Iranians to hold peaceful demonstrations.
"By announcing that they will not give permission for its opponents to demonstrate (march), the government of Iran is showing that the very activities that it praised for Egyptians it sees as illegal and illegitimate for its own people," the State Department said.
"The U.S. calls on the government of Iran to allow its own people to enjoy the same universal rights to peacefully assemble, demonstrate and communicate that are being exercised in Cairo," another tweet said.
Iranian authorities refused permission requested by opposition leaders Mirhossein Mousavi and Mehdi Karroubi to stage a rally on Monday in solidarity with the people of Egypt and Tunisia who toppled their presidents in popular uprisings.
Opposition websites on Sunday renewed calls for the rally and said authorities had stepped up pressure on pro-democracy supporters to prevent anti-government protests. Karroubi's website, Sahamnews, published a list of 18 detained activists.
The opposition's call has gained momentum on social networking websites like Facebook, with more than 48,000 people pledging to participate on one protest group's Facebook page.
Iranian authorities have portrayed the opposition movement as a foreign-backed plot to undermine the Islamic establishment, an accusation denied by opposition leaders.