Iran is preparing to swear in President Mahmoud Ahmadinejad for a second term in office, following weeks of post-election unrest in the country, BBC reported.
Opposition supporters who dispute the poll result are expected to hold protests to coincide with the ceremony.
Germany, France, Britain and the US all said they would not be sending letters of congratulation to Mr Ahmadinejad.
At least 30 people died during the street protests which followed the 12 June poll.
Mr Ahmadinejad was formally endorsed as president on Monday by Supreme Leader Ayatollah Ali Khamenei, who has solidly backed him throughout the unrest.
Mr Khamenei said Mr Ahmadinejad was the rightful winner and that Iranians had "voted in favour of a fight against arrogance, to confront destitution and spread justice".
Once sworn in, Mr Ahmadinejad will have two weeks to form a government that must then be approved by parliament.
IThe BBC's Tehran correspondent, Jon Leyne, said forming an acceptable, credible government could be the real challenge for the president.
He has been dogged by controversy in recent weeks, becoming embroiled in a series of disputes with conservative politicians who would normally be his allies.
After Monday's endorsement ceremony, witnesses said security forces prevented hundreds of opposition supporters from staging protests in Tehran.
Mr Ahmadinejad's predecessors as president - Mohammad Khatami and Ali Akbar Hashemi Rafsanjani - did not attend the event.
Also missing were the two defeated opposition candidates, Mir Hossein Mousavi and Mehdi Karroubi.
Mr Karroubi said on Tuesday that neither he nor Mr Mousavi had stopped contesting the declared election result.
"We will continue to protest and we will never collaborate with this government. We will not harm it, but we will criticise what it does," Spain's El Pais quoted him as saying.
Iran set to swear in Ahmadinejad
