Despite intense political feuding, Ahmadinejad will take his oath of office before parliament and then has two weeks to present a cabinet to the conservative-dominated assembly for approval.
Opposition websites said supporters of Ahmadinejad’s main rival, the moderate Mirhossein Mousavi, were planning to protest against the swearing-in ceremony.
A witness reported seeing hundreds of Mousavi supporters walking around the parliament building despite a heavy presence of riot police and Basij militia.
“But there is no clash,” the witness said. “Mobile phones have been cut off.”
The vote, which leading moderates say was rigged to secure Ahmadinejad’s re-election, sparked Iran’s worst unrest since the 1979 Islamic Revolution. The authorities say the vote was “the healthiest” election since the revolution.
U.S. President Barack Obama and the leaders of France, Britain, Italy and Germany have all decided not to congratulate Ahmadinejad on his re-election.
But when asked whether Obama recognised Ahmadinejad as Iran’s president, White House spokesman Robert Gibbs said: “He’s the elected leader.”
Mousavi and fellow defeated moderate candidate Mehdi Karoubi reject the new government as illegitimate, defying Iran’s most powerful figure, Supreme Leader Ayatollah Ali Khamenei, who backed the election result and endorsed Ahmadinejad.