Egypt's President Mohammed Morsi has criticized Syria's regime, calling it "oppressive," during a visit to Syria's key ally Iran.

Morsi's visit to Iran on Thursday was the first by an Egyptian leader to the Islamic Republic in three decades. It represents a major thaw in relations between the two countries since Morsi, an Islamist, became president in June in the aftermath of the country's 2011 uprising.

But the two countries remain divided over Syria's crisis. Shiite Iran backs the Damascus regime while there is widespread sympathy in Egypt for the rebels seeking to oust President Bashar Assad.

Morsi was attending a summit of the 120-member Nonaligned Movement. Egyptian officials have said they do not expect top-level bilateral meetings with their Iranian counterparts.