KABUL, Afghanistan -- The U.S. and NATO have ceremonially ended their combat mission in Afghanistan, 13 years after the Sept. 11 terror attacks sparked their invasion of the country to topple the Taliban-led government.

NATO's International Security Assistance Force Joint Command, which was in charge of combat operations, lowered its flag Monday, formally ending its deployment.

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U.S. Marines and British forces ended their combat mission in one of Afghanistan's most troubled regions. It happened in Helmand province, where ...

U.S. Gen. John F. Campbell, commander of NATO and U.S. forces, says the mission is transitioning to a training and support role. He says from Jan. 1, the coalition will maintain a force of 13,000 troops in Afghanistan, down from a peak around 140,000 in 2011.

The mission ends as the Taliban is increasing its attacks. President Obama recently allowed U.S. forces to launch operations against both Taliban and al Qaeda militants amid the training mission.

And an augmentation of the U.S. role in that training mission was announced just days before Monday's ceremony, with Defense Secretary Chuck Hagel saying about 1,000 more American troops than initially planned were to remain in Afghanistan beyond the end of the year.

At a news conference with President Ashraf Ghani, Hagel said the original plan to cut U.S. troop levels to 9,800 by the end of 2014 had been abandoned, but not because of the recent surge in Taliban attacks.

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In a ceremony Sunday morning, U.S. Marines and British combat troops officially marked the end of their operations in Afghanistan

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U.S., NATO officially end Afghan combat mission