"Task Force Tripoli has moved north and is currently conducting operations in the vicinity of Tikrit," Thorp said at Camp As-Saliyah.

"They have moved north to Tikrit from Samarra, north of Bagdad ... they're on their way, they're moving ... they're in the vicinity," he told journalists.

He declined to say whether other US troops were also headed toward the strategic northern city, but said: "The task force is one of those that is headed north."

He said the force comprised elements of the 1st Marine Expeditionary Force.

Asked whether he expected any resistance in Tikrit, Thorp said it was impossible to tell at this stage, adding "we'll be prepared if there is."

SPACE.WIRE