President Barak Obama on Friday approved sending up to 1,500 additional US troops to Iraq, doubling the number being deployed to help Iraqi forces fight the Islamic State militants.
The president also requested an additional $5.6 billion from Congress for the war against the Islamic State, in part to cover the additional deployments.
The White House again stressed that US personnel "will not be in combat", but would help in training, advising and assisting Iraqi forces near Baghdad and Irbil.
The US has been launching air strikes on Islamic State militants and facilities it controls in Iraq and Syria for weeks, as part of an effort to give Iraqi forces the time and space to mount a more effective offensive.
Early on, the Islamic State group gained ground across Iraq, as local Iraqi units threw down their weapons and fled or joined the insurgents.
Lately, with the aid of the US strikes, the Islamic State has suffered a number of losses in Iraq, where it is fighting government forces, Kurdish Peshmerga and Shiite militias aided by Iran and the Lebanese Hezbollah group.
Last week, Iraqi forces recaptured the town of Jurf al-Sakher. ISIS also lost Rabia, Mahmoudiyah and Zumar, a string of towns near the Syrian border, last month. Besieged Iraqi troops have also managed to maintain control of Iraq's largest oil refinery outside the town of Beiji north of Baghdad, despite numerous attempts by the Islamic State group to capture it.
A senior military official said one of the operations centers being set up by the US will be in Anbar province, and that it is likely that the bulk of the additional troops will be in Iraq by the end of the year.
The White House troop request comes with a $3.7-billion price tag. Of that, $3.2 billion will go to the Department of Defence while $500 million will go to the State Department.
The money will also go toward ''replenishing or replacing munitions expended while conducting air strikes against ISIL, including from Air Force and Navy platforms'' as well as ''financing operation and maintenance costs for air, ground and naval operations, including: flying hours; ship steaming days; and fuel, supplies and repair parts,'' according to the White House.
The increased number of troops will allow the US to spread its forces to additional locations across Iraq.
US Central Command will also ''establish several sites across Iraq that will accommodate the training of 12 Iraqi brigades, specifically nine Iraqi army and three Peshmerga brigades,'' Pentagon press secretary Rear Admiral John Kirby said in a statement.
Pressure has been mounting on Western nations to provide more assistance to Haider al-Abadi, Iraq's new prime minister, as Afgahn defence forces try to reclaim towns and territories in the northern and western part of the country.
American and British troops were part of the 2003 Iraq invasion that overthrew dictator Saddam Hussein.