Iraq hopes to raise billions of dollars in pledges at the three-day meeting, as the country reels from the rise of IS and punishing fightback against the jihadist group.

Baghdad declared victory against IS in December, after almost three years of war against the jihadist group that left large swathes of the country destroyed and millions displaced.

The $88.2 billion estimate was based on an assessment study by Iraqi and international experts, the planning minister said.

Qusai Abdelfattah, director general at the planning ministry, said $22 billion of those funds were needed immediately and the rest for the medium term.

"We have started some reconstruction programmes in areas affected by war," said Mustafa al-Hiti, head of the reconstruction fund for areas hit in the fight against IS.

"But what we have accomplished is less than one percent of what Iraq needs," Hiti said.

He said funds are urgently needed to "restore basic and infrastructure services" in many provinces.

"We have more than 138,000 houses damaged, more than half this number completely destroyed," Hiti said, adding that more than 2.5 million Iraqis are still displaced.

Since the 1980s, resource-rich Iraq has been battered by war and international economic sanctions.