The foreign ministers of Iran, Saudi Arabia, Egypt and Turkey are to hold their first high-level meeting on the Syria conflict on Monday in Cairo, Iran's official news agency IRNA reported.
Iranian Foreign Minister Ali Akbar Salehi was also to speak with Egypt's President Mohamed Morsi in a separate bilateral meeting during his visit to Cairo, it added.
The Fars news agency in an unsourced and unconfirmed report said the UN-Arab League peace envoy to Syria, Lakhdar Brahimi, would attend part of the foreign ministers' meeting, whose ultimate goal is to end the violence in Syria.
The gathering of the "contact group" on Syria -- an initiative by Morsi -- follows preparatory talks a week ago in the Egyptian capital by lower-ranking officials from the four countries' foreign ministries.
Salehi told the ISNA news agency before leaving Tehran on Monday that Iran would be setting out its "clear" position on its ally Syria.
"We are very hopeful given that four important countries of the region are gathered to discuss one of the sensitive issues of the region," he was quoted as saying.
The very fact the meeting was being held was "a positive step," he said, "and we hope that its results will correspond to the interests of all the people of the region, and to peace and stability."
Salehi reaffirmed that Iran was looking to expand the group to include allies Iraq and Venezuela.
As it stands, Iran is the odd member out in the regional quartet.
It staunchly supports Syrian President Bashar al-Assad, in contrast with Egypt, Saudi Arabia and Turkey which are all calling for his ouster.
On Sunday, its Revolutionary Guards admitted that members of its elite Quds Force were present in Syria, but the Guards chief affirmed they were there purely as advisors, and did not constitute a military presence.
The Guards commander, General Mohammed Ali Jafari, also said that it was undecided whether Iran would jump in militarily to help out Syria should it be attacked. He repeated Tehran's allegations that "other countries" -- taken to be Western and Gulf Arab states -- were providing material backing to Syria's rebels.
Brahimi on Sunday wrapped up a four-day visit to Syria during which he met with Assad and spoke by telephone with Free Syrian Army rebel commanders.
One of those commanders, Colonel Abdel Jabbar al-Okaidi, told AFP: "We are sure that Brahimi will fail like the other envoys before him."
Brahimi this month took over as peace envoy from former UN chief Kofi Annan, who stepped down amid discord and acrimony in the UN Security Council over how to tackle Syria.
The death toll from the conflict in Syria has risen to more than 27,000 people, according to a tally of activists' counts. The United Nations puts the toll at 20,000.
More than 250,000 Syrians have fled the violence to neighbouring countries.