Iran's President Hassan Rouhani unveiled a landmark bill of rights on Monday, guaranteeing freedom of speech, protest, fair trials and privacy, saying the achievement was "one of my oldest dreams".

Although many of the rights are already enshrined in Iran's constitution written after the 1979 Islamic revolution, Rouhani said it offered the first clear list of principles that could be used to check the performance of state institutions.

"I'm very pleased that today one of my most important promises is being delivered and I am achieving one of my oldest dreams," Rouhani told officials in a televised ceremony.

However, many institutions, including the judiciary and the powerful Revolutionary Guards, are firmly in the grip of hardliners who do not answer to the president and say the priority is to protect the revolution against dissenters and outside interference.

Rouhani said the authorities should respect limits on their powers.

"No one is allowed to enter another person's house, shop or private workplace without the permission of the owner... in the name of discovering whether crimes or sins have been committed," he said, quoting the founder of the Islamic revolution, the late Ayatollah Ruhollah Khomeini.

Having promised a bill of rights for citizens during his 2013 election campaign, Rouhani's announcement may mark a belated effort to rally reformist supporters ahead of a re-election bid in May.

Rouhani said the bill was not yet a formal law, but "must be implemented by everyone".