WASHINGTON: President Barack Obama Wednesday ordered the deployment of up to 450 more U.S. troops and establishment of a new training base in Iraq's Anbar province to help rebuild Iraqi forces in preparation for a battle to retake territory lost to ISIS.

The plan to expand the 3,100-strong U.S. contingent of trainers and advisers in Iraq marks an adjustment in strategy for Obama, who has faced mounting pressure to do more to blunt the momentum of ISIS insurgents.

Obama has not ruled out taking additional steps to fight ISIS after deciding to increase U.S. trainers in Iraq.

Obama decided on the new troop deployment in response to a request from Iraqi Prime Minister Haider al-Abadi, the White House said. The two leaders met on the margins of the G7 summit in Germany earlier this week.

But with Obama sticking to his refusal to send troops into combat or even close to the front lines, it is unlikely to silence critics who say the limited U.S. military role in the conflict is not enough to turn the tide of battle.

U.S. officials hope that a strengthened American presence on the ground will in Anbar would help Iraqi forces devise a counter-attack to retake the provincial capital Ramadi, which insurgents seized last month in an onslaught that further exposed the shortcomings of the Iraqi army.

"To improve the capabilities and effectiveness of partners on the ground, the president authorized the deployment of up to 450 additional U.S. military personnel to train, advise, and assist Iraqi Security Forces at Taqaddum military base in eastern Anbar province," the White House said in a statement.

Obama also ordered "the expedited delivery of essential equipment and material" to Iraqi forces, including Kurdish Peshmerga troops and Sunni tribal fighters operating under Iraqi command, the White House said.

It made the announcement two days after Obama said the United States did not yet have a complete strategy for training Iraqi security forces to regain land lost to ISIS fighters, who have seized a third of Iraq over the past year in a campaign marked by mass killings and beheadings.

The fall of Ramadi last month drew harsh U.S. criticism of the weak Iraqi military performance and Washington has begun to speed up supplies of weapons to the government forces and examine ways to improve the training program.

U.S. forces have already conducted training at the al-Asad military base in western Anbar but the new training facility would be at Taqaddum, which is closer to Ramadi in the eastern part of the province

U.S. officials had said earlier that planning was underway for a new installation.

A new site would allow U.S. trainers to provide greater support for Sunni tribal fighters, who have yet to receive all of the backing and arms promised by the Shiite-led government in Baghdad.

U.S. officials have said about 180 Americans have tried joining ISIS so far.