But Hillary Clinton, the US secretary of state, questioned the value of the recount.
She said: "They [the Iranian government] have a huge credibility gap with their own people as to the election process.
"And I don't think that's going to disappear by any finding of a limited review of a relatively small number of ballots."
Speaking to Al Jazeera, Ghanbar Naderi, the economic and political editor of the Iran Daily newspaper, said: "There have been some mistakes in the elections.
"There have been some minor irregularities during the election process, there is no doubt about it.
"But these minor mistakes and irregularities are not that huge to change the final result. The Guardian Council made it clear today that Ahmadinejad is the winner."
The June 12 vote unleashed the worst unrest seen in Iran since the 1979 revolution, sparking violent clashes between protesters and police, resulting in the deaths of at least 20 people.
The Guardian Council agreed to the partial recount after defeated candidates alleged that Ahmadinejad's declared victory was due to "rigged" voting.
A supervisor for the Guardian Council told Press TV, a state broadcaster, that the recount in his area showed no major irregularities.
"The results were positive, no irregularities in the results announced," the official said.
Afshin Molavi, an Iran expert at the New America Foundation, a public policy institute in Washington DC, told Al Jazeera that the "Guardian Council is not necessarily an impartial arbiter here".
Molavi pointed out that the council's members are all appointed directly or indirectly by Ayatollah Ai Khamenei, Iran's supreme leader, who has backed Ahmadinejad's victory.
"Khamenei put his stamp on this election very early on, and it would be very surprising if the Guardian Council were to do anything that would overturn that," he said.
Meanwhile, Ahmadinejad has asked a leading judge to investigate the killing of Neda Agha Soltan, a young woman who became an icon of Iran's opposition after video capturing her bleeding to death on a Tehran street was circulated worldwide.
Ahmadinejad's website said Soltan was slain by "unknown agents and in a suspicious" way, convincing him that "enemies of the nation" were responsible.
An Iranian doctor who said he tried to save Soltan told the BBC last week that she was apparently shot by a member of the volunteer Basij militia.
Also on Monday, Iran released five out of nine British embassy staff detained in Tehran.
| Ayatollah Ali Khamenei, Iran's supreme leader, has backed Ahmadinejad's win [AFP]
The release of the locally employed staff came after David Miliband, the British foreign minister, and Manouchehr Mottaki, his Iranian counterpart, discussed the situation by phone.
Hassan Qashqavi, a foreign ministry spokesman, said: "Out of nine people, five of them have been released and the rest are being interrogated."
He said Miliband had stressed that it was not Britain's intention to interfere in Iran's internal affairs.
Gordon Brown, the British prime minister, has called for the release of the final four staff, describing Iran's behaviour as "unacceptable, unjustified and without foundation".
Clinton said Iran's treatment of the British embassy staff had been "deplorable".
The workers had been detained for their "considerable role" in riots following the June 12 presidential elections, the semi-official Fars news agency had reported.
Relations between the countries have been strained after Iran accused Western powers - mainly Britain and the US - of inciting street protests after Ahmadinejad was declared the winner of the election.
Britain has denied the accusations.