Iraqi PM declares final victory in war against ISIS

Iraqi Prime Minister Haider al-Abadi has declared final victory in the war against the Islamic State on Saturday after Iraqi troops liberated the last remaining territories still under the terror group's control.

"Honourable Iraqis: your land has been completely liberated. The dream of liberation is now a reality," Abadi said in a televised address, as reported by Reuters.

"We have accomplished a very difficult mission. Our heroes have reached the final strongholds of Daesh and purified it. The Iraqi flag flies high today over all Iraqi lands," the prime minister added, using the Arabic acronym for ISIS.

The prime minister's announcement came two days after the Russian military declared the defeat of the terrorist group in neighboring Syria.

Several squadrons of helicopters carrying Iraqi flags had flown over Baghdad at noon, in what appears to be a rehearsal for a victory parade that is supposed to take place in the coming days. Abadi declared Dec. 10 as a national holiday that would be celebrated each year.

ISIS had been driven out of Mosul, the group's de facto capital in Iraq, in July following a nine-month campaign that saw much of the city destroyed. The terror group also suffered defeat in the Syrian city of Raqqa in September.

Brett McGurk, the U.S. Special Presidential Envoy to the U.S.-led coalition that supported the Iraqi forces, posted a series of tweets congratulating the Iraqi prime minister.

"We congratulate the Prime Minister and all the Iraqi people on this significant achievement, which many thought impossible," McGurk wrote.

"We honour the sacrifices of the Iraqi people, its security forces, and the Kurdish Peshmerga, and admire the unity in their ranks that had made this day possible," he added.

Abadi praised the Popular Mobilisation Forces (PMF) and Iraq's top Shi'ite cleric Grand Ayatollah Ali al-Sistani, who had issued a fatwa calling on volunteers to join the fight against ISIS.

The prime minister called for unity, which he contended was the main reason for the victory, an apparent reference to the contribution of different communities such as the Sunni tribal fighters.

"The joy of victory is complete with Iraq's unity after it was on the verge of division. The unity of Iraq and its people is the most important and greatest accomplishment," he said.

U.K. Prime Minister Theresa May also congratulated Abadi but warned that the terror group still poses a threat, including from across the border in Syria.

Last month, the Syrian military announced that it had "fully liberated" the eastern border town of Albu Kamal, which was the last stronghold of ISIS in the country.

There were some concerns that the group's foreign fighters will escape over Syria's borders to carry out more attacks abroad.