The Americans and Iraqis have responded to the influx of militants with operations to cut off the insurgents’ financing and by pursuing insurgent leaders, including Al Qaeda in Mesopotamia’s emir for the eastern side of the city who was killed in a raid late last month.

American and Iraqi units have been able to hold off the insurgents and disrupt their planning. But they have not been able to decrease the rate of attacks in Mosul, which has held stubbornly steady over the past year even as attacks have fallen in Baghdad and Anbar Province, according to an analysis by American officers.

That has prompted American and Iraqi commanders to propose the return of two Iraqi battalions that were sent from western Mosul earlier this year to bolster Iraqi forces in Baghdad. Such a move would increase the Iraqi troop strength here by 1,400 troops or more, according to estimates by American officers, and enable the Iraqis to establish more outposts in some of the more violent areas of the city.

“We are in the process of seeing what might come out of the situation in Baghdad as they consolidate down there,” said Col. Tony Thomas, the deputy commander of the First Armored Division, which has responsibility for northern Iraq. “Our biggest push, to be honest, as we looked at Mosul security is to ask for an emphasis on getting those Iraqi battalions back here.”

There are no plans to send additional American units to Nineveh Province, though the replacement of Colonel Twitty’s unit by the somewhat larger Third Armored Cavalry Regiment has led to a small troop increase. But Colonel Thomas noted that other regions north of Baghdad, like Samarra and Baiji in Salahuddin Province, and Muqdadiya in Diyala Province, had been under pressure from insurgents.