Iran is accusing Western powers of stirring up this week's violent protests in Tehran that left at least eight people dead.
President Mahmoud Ahmedinejad described the rallies as a nauseating theatrical performance staged by the United States and Israel.
French president Nicolas Sarkozy has added his voice to earlier criticisms by Britain and the United States, and condemned what he called the bloody crackdown on demonstrators.
But the Iranian foreign minister, Manouchehr Mottaki, warned the opposition not to take encouragement from the West.
Earlier a representative of Iran's Supreme Leader Ayatollah Ali Khamenei said opposition leaders were enemies of God who should be executed under the country's sharia law.
State media said the statement by cleric Abbas Vaez-Tabasi coincided with rallies by tens of thousands of government supporters calling for opposition leaders to be punished for stirring up unrest.
Authorities intensified a crackdown on the reform movement on earlier this week by rounding up leading moderates to try to end street protests.
At least 20 opposition figures have been arrested, including three senior advisers to opposition leader Mir Hossein Mousavi, his brother-in-law and a sister of Iranian Nobel Peace Prize winner Shirin Ebadi, opposition websites said.