WASHINGTON -- The United States will send another 450 military personnel to Iraq to help forces there combat the extremist Islamic State group, the White House announced Wednesday, signaling a shift in focus for the U.S. and a tacit acknowledgement that the militants have not been weakened as much as the Obama administration has claimed.

The additional personnel will establish a new U.S. training site -- the fifth in Iraq -- at Taqaddum military base in Iraq's Sunni-majority Anbar province, according to White House spokesman Josh Earnest.

Earnest said that President Barack Obama made the decision following requests from Iraqi Prime Minister Haider al-Abadi and recommendations from top military commanders and national security advisers. But the announcement also suggests a possible resolution to an ongoing struggle within the Obama administration about how best to move forward in Iraq, as military commanders have previously said that sites in Anbar province -- such as the provincial capital, Ramadi, which was captured by the Islamic State last month -- are less important than potential offensives elsewhere.

The additional U.S. forces will not play a combat role against the extremist group sometimes known as ISIS or ISIL, administration officials emphasized Wednesday afternoon in a call with reporters. Instead, they are intended to bolster Iraqi forces' morale in the embattled province, help the Iraqis respond more promptly to Islamic State advances and eventually strengthen them to the point where they can retake Ramadi and other towns like Fallujah. The officials tried to strike an optimistic tone, citing prior success at the al-Asad air base, an already-established U.S. training camp in Anbar province.

But that is a difficult message to sell in light of a Monday report from The Hill indicating trouble at the air base . U.S. military officials there are frustrated, according to the report, because the central Iraqi government has not sent new recruits to al-Asad for at least the past four weeks.

Officials on Wednesday's call said that recruitment for the new training mission will be facilitated by the Iraqi government's commitment to move closer to Sunni tribal fighters in Anbar province, something Iraqi leaders have made a priority following the fall of Ramadi. Brett McGurk , the second highest official in the U.S.-led coalition against the Islamic State, told reporters that Baghdad's decision to audit its military rolls -- removing soldiers who have fled or defected -- would free up Iraqi cash to pay more soldiers, particularly Sunni tribal recruits.

Administration officials also emphasized that Wednesday's decision had been made in response to what the Iraqis said they needed. Abadi had sought a U.S. training presence with Sunni tribesmen for some time and reiterated the request after Ramadi fell, according to McGurk.

"The Iraqis want to be in the lead themselves," said Ben Rhodes, the deputy national security adviser for strategic communications for the White House.

The statements came one day after Salim al-Jabouri, speaker of the Iraqi parliament and a prominent Sunni politician, told Foreign Policy that he blames the Islamic State's success in Anbar province not only on problems in the Iraqi forces but also on a lack of urgent U.S. attention to the problem.

The White House also announced Wednesday that it will speed up the delivery of heavy equipment, notably anti-tank missiles, to its Iraqi partners on the ground. The administration did not say whether it would directly supply the Kurdish peshmerga forces in the north or the Sunnis already battling the Islamic State, although those communities have said they desperately need supplies because they claim Baghdad is slow to distribute equipment.

The White House did not indicate how Wednesday's development will affect previously announced plans to retake Mosul, Iraq's second largest city and a key prize for the Islamic State. Military officials controversially predicted in February that Mosul would be liberated in the spring , prompting vocal criticism from Iraq and a struggle to temper expectations. The New York Times reported on Wednesday that Mosul might not be retaken until next year .

Asked about the change in policy, Rhodes did not mention whether it will affect Mosul, where residents are reportedly living in fear of the militants . Rhodes said the administration is constantly revising its approach based on reports from the ground in Iraq and Syria showing what has and hasn't worked for the U.S.-led coalition against the Islamic State.

"I wouldn't think of it as a formal review process," he said.

He added that Obama is constantly thinking about force protection as he continues to approve an expansion of the U.S. military footprint in Iraq.

Elissa Slotkin, a top defense official, said on the call with reporters that the 450 additional troops for the new U.S. training camp will be built up beginning immediately, first by redeploying forces already within Iraq and then by sending U.S. troops there from elsewhere.

CORRECTION: An earlier version of this story misattributed McGurk's comments to Rhodes.