Scarred by more than three decades of war, Iraq is recasting itself as a mediator among neighbors who are often at odds over weighty issues, including the civil war in Syria and US sanctions against Iran.
Aside from the U.S. and Saudi Arabia, the so-called Middle East Strategic Alliance would hypothetically include the UAE, Oman, Bahrain, Kuwait, Qatar, Jordan and Egypt to counter Iran, deepen defence relations, energy cooperation and deal with regional threats.
The summit will be led by Speaker of Iraq's Council of Representatives, Mohammed al-Halbusi.
Iraq's Prime Minister Adil Abdul-Mahdi recently visited both Iran and Saudi Arabia where he met with senior officials in both countries to discuss bilateral ties and further strengthen Baghdad's relationship with its neighbors.
"What binds us to our neighbours is our common geographical destiny and common interests", Mr Al Halboosi said. It is unusual for officials from Riyadh and Tehran to attend the same events.
Delegations from the six neighbouring countries at the Saturday conference pledged support for reconstruction and development efforts in Iraq, according to a statement.
Custodian of the Two Holy Mosques King Salman bin Abdulaziz held talks with Abdul Mahdi on Wednesday upon his arrival in Riyadh on an official visit. Many of Iraq's leaders, from its Shi'ite majority, have close ties with Iran, the main Shi'ite power in the Middle East.
As part of its new regional role, Baghdad has sought to restore Syria's membership of the Arab League.