The battle for Mosul, involving 100,000 Iraqi troops, members of the Kurdish security forces and popular forces, is the biggest ground operation in Iraq since the US-led invasion of 2003.
Elite Iraqi soldiers have retaken a quarter of Mosul, the terrorists' last major stronghold in Iraq, but their advance has been slow and punishing. They entered a planned "operational refit" this month, the first significant pause of the campaign.
A heavily armored unit of several thousand federal police was redeployed from the southern outskirts two weeks ago to reinforce the eastern front after army units advised by the Americans suffered heavy losses in a Daesh counter-attack.
"Right now we're staging really for the next phase of the attack as we start the penetration into the interior of east Mosul," Lieutenant Colonel Stuart James, commander of a combat arms battalion assisting Iraqi security forces on the southeastern front, said in a Reuters interview late on Sunday.
"So right now, positioning forces and positioning men and equipment into the interior of east Mosul... it's going to happen in the next several days."