Earlier in the day, Carter said that USA and coalition forces will use the airfield, recently seized by Iraqi Security Forces, as a logistical hub in advance of the upcoming battle for ISIS-held city of Mosul.
Iraqi troops backed by coalition airstrikes have pushed on the town of Qarayyah, located about 25 miles south of Mosul.
Iraqi military officials, however, said in interviews Monday that there was substantial damage to the air base that would require significant repairs. Carter, who just arrived in Iraq for an unannounced visit, said most of the troops would go to logistical, planning, and infrastructure support for Iraqi forces to launch their Mosul offensive.
Carter compared the role of Qayara to how forces used the eastern city of Makhmour, where USA troops set up a base to support advancing Iraqi units.
US officials raised the possibility ahead of Carter's arrival Monday of American military advisers working alongside Iraqi troops at lower levels than they have been to prepare for operations in Mosul.
This now brings the official number of USA troops in Iraq up to 4,647, but that doesn't include commandos or service members who remain in the country for less than four months. The announcement of the new influx of us troops into Iraq comes as Iraqi government troops and militias secured a key territory outside the Islamic State-held city.
"I am pleased to report today that. we agreed for the United States to bolster Iraqi efforts to isolate and pressure Mosul by deploying 560 additional troops", Mr Carter said at the Baghdad airport following meetings with the Iraqi premier and defence minister. United States troops in Iraq mostly advise, train and provide assistance, but are not engaged in active combat role with Iraqi forces.
USA defense officials and the Iraqi leadership hope to move on the city by the end of this year.
Fallujah was successfully captured at the end of June, with USA and Iraqi aircraft destroying a large column of IS vehicles attempting to escape. Once they fall, USA thinking goes, ISIS's attraction to young Muslims will fade.
President Barack Obama in April approved plans to allow USA troops to assist Iraqi forces at the brigade and battalion level, where they could be at greater risk, closer to the battle, but still behind the front lines.
President of Iraq's Kurdistan region Massoud Barzani and US Secretary of Defense Ashton Carter discussed on Monday the latest developments pertaining to the fight against the so-called Islamic State (IS). Prime Minister Abadi celebrated the recapture as a key step toward retaking Mosul, which is the militants' largest stronghold.
The 560 new US troops are specifically for the fight to retake Mosul. Currently, they are approved to advise at the brigade and battalion levels, but have stayed at higher levels with more senior commanders serving at the division levels of leadership. Pentagon officials have recently suggested that the fight for Mosul has slid until early 2017, but Iraq's recent battlefield successes in retaking Fallujah, Ramadi and Tikrit have led to talk that the Mosul fight could begin before the end of this year. On July 3, Islamic State suicide bombers killed at least 292 people in Baghdad's bustling Karrada area. As many as 186 were killed.
Carter and Obama have been criticized for the pace of the campaign, which began in autumn 2014 and got off to a slow start, particularly in war-torn Syria, where the United States had few assets on the ground to provide targeting information.