The New York Times said Friday the goal is to strengthen Iraqi forces to deal with a diverse array of threats after the first surge brigades leave.

Under the proposed plan, some U.S. units would continue combat roles in highly contested areas even after the number of combat brigades shrinks from 20 to 15 in mid-July, the newspaper says.

Not yet in its final form, the plan is designed to transfer more of the security burden to Iraqis without giving up the gains that have been made in recent months.

The senior U.S. commander in Iraq, Army Gen. David Petraeus, has told Congress he will not issue new recommendations until March following an assessment of conditions on the ground.