The U.S. is abandoning plans to keep U.S. troops in Iraq past a year-end withdrawal deadline. The decision to pull out fully by January will effectively end more than eight years of U.S. involvement in the Iraq war, despite ongoing concerns about its security forces and the potential for instability.

The decision ends months of hand-wringing by U.S. officials over whether to stick to a Dec. 31 withdrawal deadline that was set in 2008 or negotiate a new security agreement to ensure that gains made and more than 4,400 American military lives lost since March 2003 do not go to waste.

In recent months, Washington had been discussing with Iraqi leaders the possibility of leaving several thousand American troops to continue training Iraqi security forces.

But a senior Obama administration official in Washington confirmed Saturday all American troops will leave Iraq except for about 160 active-duty soldiers attached to the U.S. Embassy.

A senior U.S. military official confirmed the departure and said the withdrawal could allow future but limited U.S. military training missions in Iraq if requested. Both officials spoke on condition of anonymity, Sun Times reported citing the AP.