Fierce fighting is raging around the Mosul dam, Iraq's largest, as Kurdish Peshmerga troops and Iraqi forces try to recapture it from Islamic State fighters who seized it just over a week ago.
The advance of the government troops on Monday has been helped by US military airstrikes which hit at least 15 targets, according to the US Central Command.
In an interview with Al Jazeera, Qubad Talabani, deputy prime minister of the Kurdish regional government, said that while the operation is still ongoing, it is "almost complete."
"Most of the dam is now in the hands of the Kurdish forces, with the Iraqi forces, and they are clearing some of those areas, making sure there are no planted bombs," he said. "It has been a difficult, but successful operation so far."
Al Jazeera's Zeina Khodr, reporting from the town of Badriya earlier on Monday, said: "The dam is right behind me. There is smoke billowing. It is still contested territory according to a Peshmerga spokesperson.
"There is some cooperation with Iraqi forces but it is the Kurds that are waging battle - we have been to many frontlines but not seen many Iraqi forces on the ground."
Lt. Gen. Qassim al-Moussawi, an Iraqi army spokesman, said government troops have dismantled at least 170 bombs around the dam, but more bombs remain to be detonated.
The Iraqi military said that the attack had been planned days in advance and involved Iraqi anti-terrorism forces, SWAT teams and the Peshmerga.
The channel had earlier quoted the military as saying the forces had retaken the dam, backed by an air patrol. It was quickly dismissed by other sources as a premature victory statement.
The AP news agency also reported that the Islamic State has denied losing control of the dam, dismissing the government claim as "mere propaganda war.''
The statement, which could not be independently verified, was posted on a website frequently used by the armed group.
Meanwhile, the US Central Command said a mix of fighter, bomber, and remotely piloted aircraft damaged or destroyed nine Islamic State position, one checkpoint, several armed vehicles and vehicle-mounted anti-aircraft artillery gun near the dam.
"All aircraft exited the strike areas safely," the statement said.
On Sunday, the Peshmerga recaptured the town of Tel Skuf, about 15km east of the dam, as well as the towns of Sharafiya and Batnaya.
Their advance was also aided by US air strikes on Islamic State positions.
The White House said late on Sunday that the air strikes were ordered by president Barack Obama because the Islamic State's control of the dam represented a clear threat to Iraqi and US interests.
Iraq's recapturing of the entire Mosul dam complex on the Tigris river and the territory surrounding its reservoir would be a significant victory against the Islamic State group, which seized large swaths of northern and western Iraq this summer.
Speaking to Al Jazeera, Michael Stephens, the deputy director at British Royal United Services Institute for Defence and Security Studies, said: "The Mosul dam controls a lot of the water going into Baghdad, and it is one of the main water collection points for northern Iraq. It also produces hydro-electric power so it is of big strategic importance."
Seizing the dam, he added, is "in line with the Islamic State group's strategy of trying to control bigger areas of infrastructure, so they can declare that their operation is working and gain more leverage".