Iranian President Hassan Rohani will take the oath of office for his second term at a lavish ceremony in Tehran.

Rohani will take the oath in the Iranian parliament building on August 5, the final phase of his installment after Supreme Leader Ayatollah Ali Khamenei formally endorsed him on August 3.

Rohani will read out the oath and sign it, before addressing the assembled lawmakers and dignitaries.

Guests from more than 100 countries are expected, a significant achievement for Iran, which has been largely isolated since the country's 1979 Islamic Revolution.

Reports by local news agencies said that by Friday evening close to 70 foreign delegations had arrived, including European Union foreign policy chief, Federica Mogherini .

A day earlier, Amnesty international had asked Mogherini to use her visit to Iran to demand that Tehran immediately release all imprisoned human rights activists.

Under Iranian law, Rohani will have two weeks to submit his cabinet to parliament for approval.

Rohani was first elected in 2013. He won reelection on May 19 with 57 percent of the vote over conservative candidate Ebrahim Raisi.