"We hope we will not be obliged to resort to force," Prince Naif bin Abdulaziz said when asked about recent calls by Iranian figures for their pilgrims to protest against the United States and Israel while in Mecca.

"It is not permitted to undertake any actions which are not part of the ritual... and we will not permit anyone to damage the hajj or the pilgrims," he said.

But Prince Naif, who is chairman of the national hajj organization, said he did not really expect trouble.

"We have heard different Iranian statements but the most recent... from Iranian officials who are here seem to indicate that their pilgrims are going to dedicate themselves to the ritual" of the hajj, Naif told a news conference.

Earlier this month an Iranian delegation led by foreign minister Manouchehr Mottaki visited Saudi Arabia to reassure the authorities that Tehran has no intention of disrupting the hajj.

Some 3 million Muslim pilgrims take part in the hajj in the holy city of Mecca every year, including up to 2 million who travel from abroad. Hajj rituals this year start on Wednesday.

The Saudis are on particularly high alert for any security threats as Muslim pilgrims flock to the kingdom for the hajj and warned earlier this month against any attempts to politicize it.

The warning followed remarks by Iranian Supreme Leader Ayatollah Ali Khamenei to departing pilgrims that the hajj should "display the firm resolve of the Muslim nation to confront attempts that damage its unity and progress".

Iran boycotted hajj for three years after 402 pilgrims, mostly Iranians, died in clashes with Saudi security forces at an anti-U.S. and anti-Israel rally in Mecca in 1987.