Iran has suspended until at least the end of the month visa-free entry for nationals of Turkey and eight other countries, citing its hosting of a Non-Aligned Movement (NAM) summit, the Mehr news agency reported Saturday.
Turkish media have highlighted the suspension, which came amid heightened tensions between Iran and Turkey over opposing stances on the conflict in Syria.
Iran's embassy in Ankara confirmed the suspension, and said the NAM summit was the sole reason.
"The three-week suspension of the no-visa arrangement is due only to the important Non-Aligned Movement summit in Tehran," to be held August 26-31, the embassy said in a statement reported by Mehr.
"The suspension does not effect only Turkish visitors. It applies to all countries that enjoy visa-free travel to Iran," it said. It added that Turkish officials had been informed of the decision in advance.
The Non-Aligned Movement is a grouping of 120 countries which consider themselves not formally part of the world's major power blocs. Iran is to take over its rotating presidency from Egypt at the summit.
The Tehran mayor's office said 9,000 people from 120 countries are expected to travel to the Iranian capital for the summit, Mehr reported.
According to the Iranian foreign ministry, the countries having a visa-free arrangement with Iran are: Azerbaijan, Bolivia, Ecuador, Georgia, Malaysia, Nicaragua, Turkey, Syria and Venezuela.
Nearly 15,000 Turkish nationals visited Iran in 2011.
It was not immediately known whether Turkey would suspend visa-free entry for Iranians in a reciprocal step.
More than a million and half Iranians visited Turkey in 2011, according to Iranian tourism officials.
That flow has lessened this year because of the devaluation of Iran's currency against the dollar due to Western sanctions. According to the Turkish ministry of culture and tourism, some 439,000 Iranians travelled to Turkey in the first five months of this year.