US President Donald Trump congratulated Iraqi Prime Minister Haider al-Abadi on the liberation of Mosul by Iraqi Security Forces in a phone call on Tuesday.
The White House called the victory in Iraq was a major milestone in the fight against the Islamic States group, Xinhua reported.
During their talk, Trump also underscored his commitment to the total defeat of the IS and stressed the need to consolidate gains, the White House said.
Abadi declared Monday that Mosul was liberated from the IS after nine months of fierce fighting to dislodge the extremist militants from their last major stronghold in northern Iraq.
Mosul, 400 km north of Iraq's capital city of Baghdad, had been under IS control since June 2014, when government forces abandoned their weapons and fled.
The IS militants had used the city as its base and occupied some areas in Iraq's northern and western regions.