Baghdad ? The U.S. is abandoning plans to keep U.S. troops in Iraq past a year-end withdrawal deadline, The Associated Press has learned. 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 has been discussing with Iraqi leaders the possibility of several thousand American troops remaining to continue training Iraqi security forces. A Pentagon spokesman said Saturday that no final decision has been reached about the U.S. training relationship with the Iraqi government.

But a senior Obama administration official in Washington confirmed Saturday that 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 because of the sensitivity of the issue.

Throughout the discussions, Iraqi leaders have adamantly refused to give U.S. troops immunity from prosecution in Iraqi courts, and the Americans have refused to stay without it. Iraq’s leadership has been split on whether it wanted American forces to stay. Some argued the further training and U.S. help was vital, particularly to protect Iraq’s airspace and gather security intelligence. But others have deeply opposed any American troop presence, including Shiite militiamen who have threatened attacks on any American forces who remain.

Prime Minister Nouri al-Maliki has told U.S. military officials that he does not have the votes in parliament to provide immunity to the American trainers, the U.S. military official said.

A western diplomatic official in Iraq said al-Maliki told international diplomats he will not bring the immunity issue to parliament because lawmakers will not approve it.

A White House spokesman, Tommy Vietor, said discussions with Iraq about the security relationship between the two countries next year were ongoing.

Pentagon press secretary George Little said the U.S. remains “committed to keeping our agreement with the Iraqi government to remove all of our troops by the end of this year.”

“At the same time we’re building a comprehensive partnership with Iraq under the Strategic Framework Agreement including a robust security relationship, and discussions with the Iraqis about the nature of that relationship are ongoing,” Little said.