The Pentagon said on Monday it will send another 9,000 US troops to Iraq, with about half of them returning to combat ahead of schedule, in order to maintain troop levels in its new security crackdown through at least August.
Two of the affected Army units, totalling about 4,500 troops, will return to combat short of their promised year at home, reflecting the strain placed on US forces by commitments in Iraq and Afghanistan.
"What you're seeing here today reflects a decision that will carry the level of effort ... through August '07," said Pentagon spokesman Bryan Whitman. One unit will deploy 81 days short of the year-long "dwell time" at home and the second will return 47 days short of a year, Whitman said.
"This is a reflection that this is a military that is in conflict," Whitman said. "We're obviously using a significant portion of the force, combat units of the force, and it's a reflection of the realities that exist right now."
Under the Bush administration's new Iraq policy announced earlier this year, the Pentagon has increased force levels in Iraq by about 30,000 troops in an attempt to regain control of security and reduce sectarian violence.
The units announced on Monday largely replace forces already in Iraq, which number around 145,000. The Army, the largest branch of the US military, is showing signs of stress more than four years into the Iraq war. Defence officials have said commitments in both Iraq and Afghanistan have hurt the Army's ability to respond to another conflict.