The US-backed Syrian Democratic Forces (SDF) have begun an assault on the final Islamic State stronghold in Syria.
SDF official Mustafa Bali said it was “the last battle”, adding that the enclave, comprising two villages on the Iraqi border, would be “cleared soon”.
But he admitted it would be far from easy, describing the fighting focused on the village of Baghouz as “very fierce”.
He added: “Those remaining inside are the most experienced who are defending their last stronghold. You can imagine the ferocity and size of the fighting.”
The SDF waited patiently for the last 10 days, Mr Bali said, as more than 20,000 civilians were evacuated from the area.
Earlier this month, Sky News reported that Islamic State was using women and children as human shields there.
The pocket of land amounts to less than 1% of the area IS used to control after it declared a caliphate across large areas of Syria and Iraq in 2014.
Another SDF official, Redur Xelil, said commanders hope to capture the IS territory by the end of February, but warned that the terror group would continue to pose “great and serious” security threats afterwards.
The United States has echoed that comment, pointing out that IS retains leaders, fighters, facilitators and resources that could fuel an insurgency.
Donald Trump has said he expects an announcement as soon as Wednesday that the area has been reclaimed.
The US president announced in December that he was withdrawing all 2,000 US troops from Syria because the fight against IS was almost won.
That move is expected by the end of April, the Wall Street Journal reported on Friday – a date also confirmed to Reuters.