Iraqi security forces have launched an offensive to take back the city of Tal Afar from the Islamic State group.
Tal Afar and the surrounding area is one of the last pockets of ISIS-held territory in Iraq after victory was declared in July in Mosul, the country's second-largest city.
The city, 50 miles (80 km) west of Mosul, sits along a major road that was once a key IS supply route.
"You either surrender, or die," Prime Minister Haider al-Abadi said in a televised speech announcing the offensive, addressing the militants.
"The city of Tal Afar will be liberated and will join all the liberated cities."
About 2,000 battle-hardened militants remain in the city, according to US and Iraqi military commanders.
They are expected to put up a tough fight, even though intelligence from inside the city indicates they have been exhausted by months of combat, aerial bombardments, and by the lack of fresh supplies.
The city is surrounded by Iraqi government troops and Shia volunteers in the south, and Kurdish Peshmerga fighters in the north.
Shia militiamen largely stayed out of the operation to retake Mosul, which is a mostly Sunni city, but have vowed to play a bigger role in the battle for Tal Afar, which was home to both Sunni and Shia Turkmen before it fell to IS.
Some 49,000 people have fled the Tal Afar district since April, according to the UN.
Nearly a million people remain displaced by the nine-month campaign to retake Mosul, which was the militants' capital in Iraq.
Tal Afar had a pre-war population of about 200,000.
Islamic State's self-proclaimed "caliphate" effectively collapsed with the fall of Mosul. But parts of Iraq and Syria remain under its control.