The Obama administration is preparing a plan to set up a new military base in Iraq's Anbar province and send several hundred additional trainers and advisers to help bolster Iraqi forces that have struggled in the fight against Islamic State militants there, U.S. officials said on Tuesday.

President Barack Obama could give final approval as early as Wednesday to expand the U.S. military contingent in Iraq, a source close to the discussions said, marking the first significant adjustment in his strategy since the insurgents seized Anbar's capital, Ramadi, last month.

U.S. officials, speaking on condition of anonymity, expressed hope that a even a modestly beefed-up U.S. presence could help Iraq forces plan and carry out a counterattack to retake Ramadi.