Iran's President Hassan Rouhani is not "optimistic" about ongoing nuclear negotiations with world powers, the official IRNA news agency reported Monday ahead of a new round of talks this week.

"The government is not optimistic about the Westerners and the current negotiations," he was quoted as saying, echoing similar comments by supreme leader Ayatollah Ali Khamenei Sunday.

"But it does not mean that we should not have hope for removing the problems," Rouhani said, referring to international sanctions that have battered Iran's ailing economy.

The remarks came a day after Khamenei, who has final word on Iran's nuclear drive, said he is not optimistic about the talks but supports them as they are incapable of hurting the Islamic republic.

"I am not optimistic about the negotiations but, with the grace of God, we will not suffer losses either," said Khamenei.

"I do not think the negotiations will produce the results expected by Iran," he added.

World powers are set to resume talks with Iranian negotiators in Geneva on November 7 and 8, to build up on a "substantive" meeting last month when Iran tabled a new proposal.

Western powers and Israel suspect Iran is pursuing nuclear arms in the guise of a civilian programme, accusations repeatedly denied by Tehran.