“We believe that in this historic moment we can say that what brings us together as countries and peoples in our region is bigger than what separates us,” Mr Al Kadhimi said, addressing leaders and senior officials from nine countries.
He appealed for support to his country which is still struggling to maintain stability after decades of war and internal strife.
“We look forward to co-operation and support from all friends and neighbours to modernise Iraqi cities through investment and sustainable development,” he said.
Speaking after Mr Al Kadhimi, French President Emmanuel Macron pledged his country's continuing support to Iraq in the fight against terrorism and training Iraqi security forces.
"Today's meeting shows that the will to co-operate and build partnerships remains the most important thing to achieve peace in this key region," Mr Macron said through an Arabic interpreter.
"We owe the people of Iraq to regain control of its fate and return to stability and development. France remains fully committed to the Iraqi forces on the ground, in both their combat missions and training."
"I would like to say that France will remain committed to be on your side to fight terrorism as long as you [Iraq] sees that as necessary and needed," he added.
The one-day Baghdad Conference for Co-operation and Partnership is being held in co-ordination with France and is planned to ease tensions in the region and boost co-operation between its countries.
In addition to Mr Macron, UAE Vice President and Ruler of Dubai Sheikh Mohammed Bin Rashid, Egyptian President Abdel Fattah El Sisi, Jordan's King Abdullah II, Qatar’s Emir Sheikh Tamim and Kuwaiti Prime Minister Sheikh Sabah Khaled Al Hamad Al Sabah are attending.
On the sidelines of the conference, Sheikh Mohammed met with Sheikh Al Sabah where the two leaders discussed "ways to enhance bilateral relations in the best interests of the two countries," according to a statement on official UAE news service WAM.
Sheikh Mohammed remarked on Twitter that the summit represented Baghdad's revival of its "regional and global position" and a return to "writing a new story in the march of civilisation".
Sheikh Mohammed also held a separate meeting with Sheikh Tamim Bin Hamad Al Thani, Emir of Qatar. The leaders discussed the conference and "its anticipated outcomes geared towards serving the lasting security and stability of Iraq, wishing the conference great success and progress and prosperity for the Iraqi people."
"The Gulf destiny is one..it was and will remain," Sheikh Mohammed said in a tweet.
Sheikh Mohammed and Kuwaiti Prime Minister separately met Iran's Foreign Minister Hossein Amir-Abdollahian.
Saudi Foreign Minister Prince Faisal bin Farhan said the summit “comes at a time when the region and the world are witnessing changes and that we all need to increase co-operation in order to face them and achieve the aspirations of our peoples, for security and prosperity.”
Iran’s new Foreign Minister Hossein Amir-Abdollahian, Turkish Foreign Minister Mevlut Cavusoglu and their Saudi Arabia counterpart Faisal bin Farhan Al Saud are also present.
Ambassadors of the permanent members of the UN Security Council, the EU, members of the G20 group, the Gulf Co-operation Council and the Arab League are attending as observers.
Syria has not been invited, following intense political controversy in Baghdad after a pro-Iran politician informally invited President Bashar Al Assad in early August. The Iraqi Ministry of Foreign Affairs later clarified that only the ministry could send official invitations.
The region has been rocked by a series of crises in recent years that have strained relations between governments.
Ongoing wars in Syria and Yemen, the economic collapse in Lebanon and instability in Libya have ensured tensions have remained elevated.
Iran’s controversial nuclear programme is also viewed by many countries – mainly the Gulf States – with suspicion. Relations between Qatar and Saudi Arabia and other Gulf States have only recently improved.
Iraq 's mediating role
Iraq sees a benefit in boosting relations with Arab countries and mending relations between rivals in the region, mainly Iran and Saudi Arabia.
Iraq has been in the grip of multiple challenges since the 2003 US-led invasion that toppled Saddam Hussein and unleashed insurgency and sectarian warfare.
It had been shunned by Arab countries, who believed its Shiite-led government was too close to Iran.
Since then, the country has been a battleground for settling scores.
Iraq has been caught in the middle as its main allies, the US and Iran, sparred on its soil. The situation came to a head on January 3, 2020, when a series of clashes between Iran-backed militias and US forces led to President Trump authorising a drone strike near Baghdad airport against Iranian general Qassem Suleimani.
That nearly brought Iran and the US to the brink of war as Iran fired a volley of ballistic missiles towards US bases in Iraq, injuring 100 US soldiers.
Iraq's oil-dependent economy has also repeatedly stalled as oil prices have seen calamitous drops since 2014, reaching a low point in 2020 during the Covid-19 pandemic. The war-torn nation also needs billions of dollars for post-war rebuilding efforts.
Iraqi officials are planning to have representatives of Iran and Saudi Arabia sitting in a parallel meeting to continue discussions Baghdad hosted in recent months.
After backing opposing sides during the Syrian civil war, Iran and Saudi Arabia are now aligned with rival forces fighting a war in Yemen, and severed their relations in 2016.
Relations worsened after a 2019 missile and drone attack on Saudi oil infrastructure at Abqaiq briefly knocked out half of Saudi Arabia's oil production. Riyadh, the US and the UN blamed the attack on Iran, a charge Tehran denied.
But despite these tensions, the conference showed widespread support for Iraq's efforts to mediate regional conflict.
"Our meeting at the conference is evidence of Iraq's central role," said Jordan's King Abdullah. "We must open all doors to achieve economic integration," he added.
Mr El Sisi praised Iraq's famed ancient heritage while highlighting warming relations between Cairo and Baghdad.
"You are an ancient nation that enjoys a special standing, a civilisation, a history and diversity ... protect your country, build, develop and participate. Build you future and the future of your children," he said.
Mr El Sisi has in recent months forged close relations with the Iraqi leader and laid the foundations of a regional alliance that groups Egypt, Jordan and Iraq. He alluded to that alliance in his comments on Saturday, saying that partnership opens the way to broader and cooperation.
In a thinly-veiled reference to Iran, Saudi Foreign Minister said his country rejects foreign intervention in Iraq and other Arab and Islamic countries in the region.
“The kingdom stresses on the importance of respecting the sovereignty of Iraq and Arab and Islamic countries in the region and rejecting foreign intervention in some Arab countries,” he said.
Egyptian President Abdel Fatah El Sisi echoed the same concerns regarding Iran and Turkey.
"Egypt rejects all kinds of foreign intervention in the affairs of Iraq along with the illegitimate aggressions on its territory,” Mr El Sisi said.
“It calls on all powers to respect the sovereignty of this ancient nation and the choices of its people. Everyone benefits from Iraq assuming its Arab and regional role," he added.
For his part, the Iranian foreign minister blamed the US for the instability in the region, calling for dialogue among the regional countries away from “intervention from foreign countries.”
“The Americans do not bring peace and security to the peoples of the region,” Mr Amir-Abdollahian said, delivering his speech in a classical Arabic in what is seen as an attempt present Iran as part of the region and not to be treated as an outsider.
"They were the main reason behind the insecurity in the region."
But the conference's final communique set a very different tone, emphasising regional cooperation to improve security.
The communique vowed to back Iraqi government efforts in post-war reconstruction, to improve public services and infrastructure and to deal with the challenges arising from climate change and global warming.
Iraqi Foreign Minister Fuad Hussein hailed the meeting as a success for “bringing together leaders from rival countries and creating an atmosphere of dialogue between countries in conflict”.
Today’s event “will have future impact on the situation in Iraq and the region and will reduce tensions and pressures,” Mr Hussein told reporters after the summit.
He added that there will be more follow-up meetings by with foreign ministers and another meeting may be held in Amman next year, with the possibility of inviting more countries.
Hamza Hendawi contributed to this report from Cairo, Egypt.