Iraqi and Afghani Presidents Jalal Talabani and Hamid Karzai arrived on Saturday for talks with their Iranian counterpart Mahmud Ahmadinejad to mark Nowruz, or the new year, the official IRNA news agency reported.

Nowruz, meaning "new day" in Farsi, marks the transition from winter to spring, as well as the start of a new year in Iran and Afghanistan, with an estimated 300 million people observing the regional holiday.

For the second year running Iran invited regional leaders to celebrate the Nowruz holiday as a "symbol of peace".

Leaders of Tajikistan, Turkmenistan and Armenia, along with the Crown Prince of Qatar and the foreign minister of Oman are expected to take part in the festivities which include meeting Iran's supreme leader Ayatollah Ali Khamenei.

In recent weeks, conservative leaders have criticised the decision to celebrate Nowruz in the face of the wave of protests across the Arab world, but the government decided to go ahead with the event.

"Organising this holiday highlights that Iran is a hearth of peace, cordiality and calm," said an Iranian presidential aid.