U.S. officials are hailing the latest push by Iraqi forces into Mosul, confirming reports that a key government building has been retaken from Islamic State fighters.
A senior U.S. defense official said Friday that Iraqi forces had captured the Ninevah province council building from the terror group and had raised the Iraqi flag.
"It's both a symbolic victory and a significant operational victory," acting Assistant Secretary of Defense Elissa Slotkin told reporters during a Pentagon briefing.
"[We are] thrilled to see the success continue and that we've got the momentum that's so required," she added.
Also Friday, Iraqi special forces stormed Mosul University, taking control of a neighborhood to the northeast, as well as some parts of the campus. Witnesses said IS was putting up a fight and reported heavy clashes in some areas.
"Work still needs to be done. But ISIL's days in Mosul are quickly coming to an end," Operation Inherent Resolve spokesman Colonel John Dorrian said in a statement, using another acronym for the Islamic State group.
WATCH: Mosul Government Complex Captured
Much of the latest progress to retake Mosul has come in the city's east. But a spokesman for Iraq's counterterrorism service told Reuters that its forces also had reached two of the five bridges connecting the eastern and western parts of the city, which are separated by the Tigris River.
Still, U.S. defense officials remained cautious, warning the fight against IS in Iraq was most likely far from over.
"Beyond Mosul, we are going to need a strong coalition presence, because the fight is not done," said Slotkin.
"They [IS] are in western Iraq, and that border needs to be re-established," she added. "We have some areas that remain an open plain, and we've seen ISIL in the past exploit that."
There have been questions about how the U.S. role in the fight against IS in Iraq and Syria may change, with some officials of the incoming administration of President-elect Donald Trump having talked openly about speeding up the campaign.
Slotkin said Pentagon officials have been meeting with members of the Trump transition team, describing the talks as "very open." She also said, however, there is only so much more the U.S. and the coalition can do.
"We have a plan in place right now," she said, referring to the group's Syrian stronghold of Raqqa as an example. "It moves as fast as local forces on the ground are able to move."