An American man of Iranian descent, accused by Iran of spying for the U.S. Central Intelligence Agency, went on trial in Tehran on Tuesday, the semi-official Fars news agency reported.

Iranian authorities announced Amir Mirza Hekmati's arrest earlier this month. State television has shown a taped interview with him in which Hekmati said he was a CIA agent.

In the indictment (read in court), Hekmati was charged with cooperating with the hostile government of America as well as spying for the CIA, Fars reported.

It said the indictment was based on information provided by Iran's intelligence ministry as well as Hekmati's own confession.

In court on Tuesday, Hekmati confessed to having links with the CIA but said he had no intention to harm Iran.

I was deceived by the CIA ... Although I was appointed to break into Iran's intelligence systems and act as a new source for the CIA, I had no intention of undermining the country, Fars quoted Hekmati as saying.

Later Hekmati's lawyer presented his defence and criticised the indictment but that was rejected by the prosecutor.

Iran's Intelligence Ministry has said Hekmati had received training at U.S. bases in neighbouring Afghanistan and Iraq.

Current and former U.S. government officials told Reuters in November that Iran had succeeded in uncovering the identities of several CIA informants.

Iran said in May it had arrested 30 people on suspicion of spying for the United States and later 15 people were indicted for spying for Washington and Israel. Spying in Iran can be punishable by death.

The United States is leading efforts to tighten sanctions on Iran which it accuses of seeking nuclear weapons, a charge Tehran denies. Washington and Israel say they do not rule out making military strikes on Iran's nuclear sites if diplomacy fails.

(Writing by Ramin Mostafavi Editing by Maria Golovnina)