A triumphant Iraqi Prime Minister Haider al-Abadi declared on Monday that the coming year will see his forces defeat Islamic State, after his military achieved its first major victory since collapsing in the face of the fighters 18 months ago, reported Reuters.

“Yes, the city of Ramadi has been liberated. The Iraqi counter terrorism forces have raised the Iraqi flag over the government complex in Anbar,” joint operations spokesman Brigadier General Yahya Rasool said in a statement broadcast on state television.

Iraqi forces flew the national flag above the main government complex in Ramadi earlier in the day, declaring they had recaptured the city, a provincial capital west of Baghdad which fell to Islamic State fighters in May.

“2016 will be the year of the big and final victory, when Daesh’s presence in Iraq will be terminated,” Abadi said in a speech broadcast on state television, using an Arabic acronym for Islamic State that the hardline group rejects.

“We are coming to liberate Mosul and it will be the fatal and final blow to Daesh,” he added. Mosul, northern Iraq’s main city, is by far the largest population centre in the self-proclaimed caliphate Islamic State rules in Iraq and Syria.

According to JPost, the capture of Ramadi, capital of mainly Sunni-Muslim Anbar province in the Euphrates River valley west of the capital, deprives Islamic State militants of their biggest prize of 2015. The fighters seized it in May after government troops fled in a defeat which prompted Washington to take a hard look at strategy in its ongoing air war against the militants.

Soldiers were shown on state television on Monday publicly slaughtering a sheep in an act of celebration.

Gunshots and an explosion could be heard as a state TV reporter interviewed other soldiers celebrating the victory with their automatic weapons held in the air. A separate plume of smoke could be seen nearby.

U.S. Army Colonel Steve Warren, a spokesman for a U.S.-led coalition backing Iraqi forces, said in a statement: “The clearance of the government centre is a significant accomplishment and is the result of many months of hard work.”

He said the coalition had provided more than 630 airstrikes in the area over the past six months as well as training, advice and equipment to the army, counter-terrorism forces and police.

The U.S.-led coalition, which includes major European and Arab powers, has been waging an air campaign against Islamic State positions in both Iraq and Syria since a third of Iraqi territory fell to the fighters in mid-2014.

The government said the next target after Ramadi will be the northern city of Mosul, by far the largest population center controlled by Islamic State in either Iraq or Syria.

Dislodging the militants from Mosul, which had a pre-war population close to 2 million, would effectively abolish their state structure in Iraq and deprive them of a major source of funding, which comes partly from oil and partly from fees and taxes on residents.