Holding other high level consultations is also on the agenda of the Iranian president.
The SCO members and observers present in the summit are supposed to voice their full support for the 2015 Iran nuclear deal with five permanent members of the UN Security Council - the US, the UK, France, Russia and China - plus Germany.
According to some media reports, China and Russia and other member states are likely to put Iran's full membership in the SCO on their agenda of the summit as sign of support for the Iran Deal, known as the Joint Comprehensive Plan of Action (JCPOA).
One of the most important topics discussed on the sidelines of the summit was the issue of backing the Iran nuclear deal to an extent that Russian President Vladimir Putin and his Chinese counterpart Xi Jinping in their Friday evening's meeting announced their full support for the JCPOA.
Both the Russian and Chinese presidents vowed that they will do their best to save the JCPOA.
Leaders of other member states in their separate meetings with the Iranian president on the sidelines of the summit threw their weight behind the deal and called for its preservation.
On Saturday, the Iranian and Russian president discussed ways of strengthening Tehran-Moscow political and economic ties. They also reviewed the latest developments concerning the JCPOA in the wake of US unilateral exit from it.
Rouhani in a meeting with his Pak counterpart Mamnoon Hussain reviewed issues of mutual interests.
Rouhani said at the meeting that strengthening banking ties would play an important role in developing economic relations between Tehran and Islamabad. He also announced Iran's readiness for making joint investments with Pakistan in various fields.
Referring to the IAEA's verification of Iran's compliance with all its obligations under the JCPOA, Rouhani said the US unilateral exit from the international deal ran counter to all international rules and regulations as well as the UN Security Council resolutions to which the international community should react.
The Pakistani president, for his part, referred to deep cultural and historical commonalties between the two countries, saying Pakistan, as a friendly and neighboring country will always stand by Iran.
He said Pakistan considers the development of Chabahar port in the southeastern province of Sistan-Baluchestan, to be in the interest of the whole region and called for a boost in mutual trade exchanges using all capacities and removing existing obstacles.
President Hussain once again expressed Pakistan's support for Iran's full membership in SCO and lauded the Islamic Republic's positive role in the organization as an observer country.
Pakistan supports the JCPOA and urges all sides to remain committed to it, the Pakistani president said.
Underlining the importance of the two countries' regional cooperation, Hussein said peace and stability in Afghanistan was important for Tehran and Islamabad.
Meanwhile, Iranian President Hassan Rouhani in a meeting with his Afghan counterpart Ashraf Ghani expressed support for peace and security in Afghanistan.
He described a secure and stable Afghanistan as a requirement for regional security and development.
The Islamic Republic of Iran will spare no effort to maintain peace and fight terrorism in Afghanistan, President Rouhani added.
Over the past 40 years, Iran has always stood by Afghanistan, he said, adding that both countries enjoy common culture, security and trade interests.
Expressing hope for facilitating the implementation of cooperation agreement between the two countries, President Rouhani said that Iran is determined to develop relations with its neighbors, especially Afghanistan, and setting up joint investment in various projects namely transit and transportation infrastructure.
President Ghani, for his part, urged both sides to accelerate economic relations.
He said that Afghanistan considers developing relations with Iran in line with its national interests.
'Developing Chabahar Port is not only important for Iran, Afghanistan and India, but for promoting ties between China and Central Asia,' President Ghani added.
Elsewhere in his remarks, the Afghan president expressed readiness for maintaining all-out ties with Iran in fighting drug smuggling.
In another development, Rouhani and Belarusian President Alexander Lukashenko in a meeting in Qingdao on Saturday discussed ways to promote bilateral relations.
Terming Tehran-Minsk relations as growing in various fields, Rouhani called for deepening of bilateral ties using all existing potential and capacities in both countries.
Belarus has always been a friendly country for Iran and Tehran is ready for promotion of mutual ties in various field of economy and trade particularly science and modern technology.
President Lukashenko said his country is determined to broaden political and economic relations with Iran as a key partner of Belarus in the region.
He also described as 'wise' Iran's stance on the US unilateral withdrawal from the JCPOA and said unilateral actions and breaches of international obligations would endanger international law.
Founded in 2001, SCO is an organization with eight member states and four observers including Iran. The organization aims at taking measures to counter terrorism and extremism and promote economic cooperation.
In the 2016 summit of SCO held in Tashkent, representatives of India and Pakistan signed documents for full membership of the organization and their demands were approved in the 17th meeting of the organization in Astana, Kazakhstan.
The organization covering a total area of 35,972,000 square kilometers and an overall population of three billion has turned into one of the largest regional powers in the world, insuring political, economic, social and cultural benefits for its member states at bilateral and multilateral levels.
China, a founder and key member of the organization, has been Iran's biggest trade partner and its largest purchaser of Iranian crude oil. It was also a member of G5+1 in nuclear talks with Iran.
In 2017, the trade exchanges between Iran and China stood at 37.3 billion dollars registering a 20 percent rise compared with 2016. In the same year, Iran exported 630,000 barrels of oil per day to China.
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