Over 2,000 Islamic State group fighters have been killed or put out of action by Iraqi and US-led coalition forces in Mosul since October, the top US commander in Iraq said Sunday.
"By our calculations, we think we have killed or badly wounded over 2,000," Lieutenant General Stephen Townsend said at a news conference held jointly with US Defence Secretary Ash Carter at Qayara air base.
According to Townsend, an estimated 3,000 to 5,000 IS fighters are still battling to keep control of Mosul. He also praised the efforts of US and Iraqi forces, while disputing suggestions that IS have forced a stalemate in Mosul.
"I don't think that suggests anything about a stalemate," Tonwensed said while highlighting the allegedly high IS death toll. "This is a major urban area. Any army on the planet - including the United States Army - would be challenged by this fight."
"The Iraqi army has come back from near-defeat two years ago, and now they are attacking this major city 400 kilometres from Baghdad," Townsend said. "I don't think there is anything in there about a stalemate."
Townsend added that according to US intelligence, there were around 3,500 to 6,000 IS fighters in the city.
US officials declined to say how many Iraqi government troops have been killed so far in the battle for Mosul.
On Sunday, Carter made an unannounced visit to the Qayara base, flying in from Baghdad after meeting with Prime Minister Haider al-Abadi.
It was Carter's first visit to Qayara since it began operating as an Iraqi staging base in October.
"Everything is going according to the plan of a year ago," Carter said during the trip.
Carter recently claimed that the battle for Mosul could be over before US president-elect Donald Trump takes office in January. Such a feat, however, would require a huge step-up in the coalition's current progress.
Iraq's army, backed by loyalist Shia and tribal militias, Kurdish fighters and a US-led coalition have been fighting to unseat the IS group from their Iraqi 'capital' of Mosul for around two months.
Around a quarter of the city has already been recaptured by the army, however militants are puting up stiff resistance in the battle for one of the last major strongholds.