The "Baghdad II" meeting in Jordan, which alongside regional powers also includes officials from France and the European Union, follows an August 2021 summit in Iraq's capital organised at the initiative of Macron.
"There is a way that is not... a form of hegemony, imperialism, a model that would be dictated from outside," Macron told the summit at Sweimeh, a resort on the shores of the Dead Sea.
Iraq has been caught for years in a delicate balancing act between its two main allies, the United States and Iran, and Baghdad only recently arrived at a fragile compromise government after a year of political stalemate.
It has endured nearly two decades of turmoil since the US-led invasion toppled dictator Saddam Hussein in 2003.
The jihadist Islamic State group seized roughly one third of Iraq and declared a "caliphate" in 2014, before its defeat more than three years later.
"Iraq today is the scene of influences, incursions, destabilisations that are linked to the entire region," Macron said.
The summit in neighbouring Jordan was aimed at providing "support for the stability, security and prosperity of Iraq", the French presidency said, adding it hoped this would benefit "the entire region".
'No One Expects Miracles'
Several countries in the region are mired in unrest. Syria remains a battleground for competing geopolitical interests, and Lebanon is stuck in an economic and political quagmire.
For over three months, Iran has bloodily suppressed a wave of popular demonstrations sparked by the September 16 death in custody of Mahsa Amini, a 22-year-old Iranian woman of Kurdish origin.
The meeting was also being attended by the EU's top diplomat, Josep Borrell, who has been mediating talks aimed at reviving the 2015 Iran nuclear deal.
Borrell met with Iran's Foreign Minister Hossein Amir-Abdollahian, talks the EU diplomat said were "necessary... amidst deteriorating Iran-EU relations".
French Foreign Minister Catherine Colonna said she briefly spoke with Amir-Abdollahian and demanded the release of seven French "hostages" in Iran and the respect for civil and political rights.
Colonna also urged the "speedy election" of a president in Lebanon and the formation of a new government to "carry out badly needed reforms".
Lebanon's cabinet is acting in a caretaker capacity, and the country has been without a head of state for more than a month.
The summit also brings together Iraq's new Prime Minister Mohammed Shia al-Sudani as well as delegations from Turkey and Saudi Arabia.
"This summit has great ambitions but no one expects miracles," said Riad Kahwaji, director of the Institute for Near East and Gulf Military Analysis.
Test For Iraq
France's role as a mediator is crucial, Kahwaji said, with Paris "keeping the thread of dialogue on behalf of Westerners with Iran, especially as the Vienna nuclear negotiations are currently in stalemate".
Iran's involvement in the Ukrainian conflict through the supply of drones to Russia further complicates the discussions, Kahwaji said.
Tehran has accused regional rival Saudi Arabia, with which it has had no diplomatic relations since 2016, of fomenting unrest in Iran as protests rage on.
Ahead of the summit, Iran's Amir-Abdollahian said Tehran was "ready to return to normal relations" with Riyadh "whenever the Saudi side is ready".
The conference is also a test for Iraq's Sudani, appointed prime minister in late October after more than a year of political deadlock.
Considered closer to Iran than his predecessor, Mustafa al-Kadhemi, this is Sudani's first major international meeting.
Hamzeh Hadad, a visiting scholar at the European Council on Foreign Relations, said the first summit in 2021 had been intended to allow Kadhemi to show he could "gather neighbouring leaders, in particular the Gulf states, in Baghdad".
During this meeting, Sudani will have to demonstrate "he can maintain these relations and show that they do not depend on personal ties", Hadad said.
The meeting was also expected to address issues such as global warming, food security, water resources and energy cooperation.