The attempt by Turkish Prime Minister Recep Tayyip Erdogan, the new chair of the Organisation of Islamic Cooperation, to mediate between Saudi Arabia and Iran, at the summit this week did not succeed.

“We tried to get them together; the Iranians were open or I should say maybe more open than the Saudis; the Saudis put too many conditions; it did not work,” said a Turkish diplomat who asked to remain anonymous.

Erdogan was working to get King Salman of Saudi Arabia and President Hassan Rouhani of Iran, who were both in Istanbul throughout Thursday for the OIC summit, to a meeting that could have eased regional tensions.

The Turkish attempt was supported by US diplomacy, according to the same Turkish diplomat.

He said that what the Saudis wanted ahead of any summit meeting was a promise of change in Iran's support for the regime of Bashar Al-Assad in Syria.

Riyadh is determined to overthrow Al-Assad, and also wants Iran to stop supporting Hezbollah in Lebanon and Syria.

But the three-way meeting was not held. Instead, diplomats from some OIC member states told Ahram Online, the Saudis executed a stronger-than-ever-before influence on the Islamic grouping, forcing the passing of a resolution that warns Iran against intervening in the internal affairs of other member states and that negatively brands Hezbollah.

“The Conference rejects Iran's inflammatory statements on the execution of judicial decisions against the perpetrators of terrorist crimes in the Kingdom of Saudi Arabia, considering those statements to be blatant interference in the internal affairs of the Kingdom of Saudi Arabia and a contravention of the United Nations Charter, the OIC Charter and of all international covenants," the OIC statement read.

"The Conference deplores Iran's interference in the internal affairs of the States of the region and other Member States including Bahrain, Yemen, Syria, and Somalia, and its continued support for terrorism," it added.

The statement also condemned the attacks on Saudi missions in Iran in January.

Ultimately, the OIC summit emphasised "cooperative relations between member countries and Iran" that would be based on "the principle of good-neighbourliness, non-interference in their domestic affairs, respect for their independence and territorial sovereignty."

Both Salman and Rouhani were not present at the final session of the summit on Friday afternoon.

The resolutions adopted in the closing session of the OIC's highest meeting came as no surprise to the Iranians, given that the preparatory meetings that were held in Istanbul a few days ahead of the summit at the ministerial level had taken place without their attendance.

Iran had already slammed Saudi Arabia’s "destructive" move to include statements against the Islamic Republic and Lebanon’s Hezbollah resistance movement in the draft declaration of summit.

Iranian Foreign Minister Mohammad Javad Zarif had said on Wednesday, the eve of the opening of the summit, that Riyadh’s efforts to see four anti-Iranian paragraphs included in the summit's draft declaration and another against Hezbollah were against the “spirit of Islamic solidarity.” which can only serve the interests of the Israeli regime, IRNA agency reported.

Diplomats attending the summit told Ahram Online that at the closing session Iranian diplomats were promising that the organisation would regret taking the side of Saudi Arabia against Iran.

“I am not sure that this is the end of our efforts to bring the two sides together; you know with diplomacy there are always several attempts during which you are bound to hear some strong, angry statements from all sides,” the Turkish diplomat who spoke to Ahram Online over the phone said.

He accepted however that “for now” it could well be argued that Saudi Arabia has successfully sent Iran a strong message that it is expanding its regional influence.

The OIC summit came a few weeks after Saudi Arabia had hosted and chaired one of the largest military manoeuvres in the region, the “Thunder of the North”, with 20 Muslim states, not including Turkey, which is a NATO member.

"True, but it is also coming at a time where the Saudis are hosting some of the leading figures from the Houthis of Yemen to find a compromise,” the Turkish diplomat said.

Saudi Arabia started a war against the growing political strength of the Houthis – said by Riyadh to be supported by Tehran – in Yemen over a year ago. Recently, it has been trying to reach a deal between its traditional supporters in Yemen, the immediate strategic backyard of the oil rich kingdom, and some of the Houthi leaders, to end a war that is said by European sources to be going nowhere.

Arab diplomats present at the summit say that it is clear that Saudi diplomacy is moving ahead with establishing Riyadh as the uncontested leader of the region: “I mean this is clear from its relations with Egypt and it is clear from its gains in the Turkey-hosted OIC summit,” said a diplomat from North Africa.

This “diplomatic” ammunition, Arab diplomats suggest, would be used by Riyadh when it receives US President Barack Obama on Wednesday for a meeting with the leaders of the Gulf Cooperation Council.

The US has been putting pressure on its long-time Gulf ally recently to open up to Iran. Obama has openly criticised the failure of the Saudis to live up to the demands of regional stability, and he said recently that the assailants in the 9/11 attacks were mostly Saudi, not Iranian.

Iran and regional stability at large are to figure high in the Riyadh talks. Also on the agenda of the unusually tense meeting are the Saudi threats to sell off hundreds of billions of dollars’ worth of American assets held by the kingdom if Congress passes a bill that would allow the Saudi government to be held responsible in American courts for any role in the September 11 attacks.