Even in Iraq, where the jihadists lost more ground and only retain seven percent of the territory they once had, declaring the caliphate dead "implies that IS can no longer control terrain and govern", he said.
Iraqi forces, backed by US-led air strikes, have tried to retake the city since 17 October past year.
Thirty IS militants were killed as they attempted to escape the advance of the Iraqi forces by throwing themselves in the River Tigris, state media said.
Backed by a ferocious aerial bombing campaign by a US-led worldwide coalition, the offensive has turned much of the city to rubbleand forced tens of thousands of people to flee. "The Iraqi progress, backed by the army air power, is great", spokesman for the Mosul operation, Brigadier Yehia Rasoul, told state television al-Iraqia.
The mood was less festive, however, among some of the almost one million Mosul residents displaced by months of combat, many of whom are living in camps outside the city with little respite from the blazing summer heat.
"The fighters of Islamic State are collectively pledging [to fight to the] death in Maydan", the agency said.
Some Iraqi soldiers celebrated, dancing with rifles and machineguns and waving the national flag as they reached their assigned targets, without waiting for a formal victory announcement to be made, a Reuters TV crew said.
In mid-2014, ISIS overran the city, which now represents the embattled terrorist group's last stronghold in northern Iraq.
The offensive on Mosul's Old City began on June 19, after government troops regained control of the other districts in the city in previous months.
In one of the biggest achievement in the war against the Daesh, Iraq has claimed that it has captured the city of Mosul from the terror group.
The Iraqi government does not reveal casualty figures, but a funding request from the U.S. Department of Defense said the elite Counter Terrorism Service (CTS), which has spearheaded the fight in Mosul, had suffered 40 percent losses.
Iraqi forces have been backed by United States forces and on Sunday said they had reached the banks of the Tigris.
Numerous nearly one million residents displaced by the conflict are living in camps outside the city.
"Mosul liberated from ISIS: France pays homage to all those, who alongside our troops, contributed to this victory", Macron said on his Twitter account.