"I hope you (Obama) will avoid interfering in Iran’s affairs and express regret in a way that the Iranian people are informed of it," the semi-official Fars News Agency quoted Ahmadinejad as saying.

Ahmadinejad also said Obama is repeating what "Bush used to say" about Iran, Reuters reported, citing the Iranian news agency.

"Mr Obama made a mistake to say those things ... our question is why he fell into this trap and said things that previously (former U.S. President George W.) Bush used to say," he said.  

Ahmadinejad was speaking in the port town of Assaluyeh, where he was inaugurating a petrochemical plant.

Since taking office Obama has made diplomatic overtures towards Iran, after three decades of severed ties and a standoff over Tehran’s nuclear drive.

But as the unrest has mounted in Iran over the disputed presidential election that returned Ahmadinejad to power, Obama has been increasingly critical of the vote and the crackdown on opposition protesters.

In his most recent comments, Obama said there were significant questions about the election results and that he was "appalled and outraged" by the violent suppression of the protests.

The Washington Times reported on Wednesday that Obama’s administration wrote to Iran’s supreme leader Ayatollah Ali Khamenei before the election offering to improve relations.