WASHINGTON - The United States hopes to end its combat mission in Afghanistan by the middle of next year, more than a year earlier than planned, and will focus instead on a training, advisory and assistance role, US Defense Secretary Leon Panetta was quoted on Thursday as saying.

"Our goal is to complete all of that transition in 2013 and then hopefully by mid- to the later part of 2013 we'll be able to make a transition from a combat role," Panetta was quoted by the Washington Post as telling US reporters Wednesday en route to a NATO defense ministers' meeting in Brussels.

Panetta's remarks reflected a growing sentiment within the Obama administration that its approach to Iraq, where the official end of US combat operations came 16 months before the final troop withdrawal in December, may provide a useful model for winding down operations in Afghanistan, the Post reported.

According to the NATO strategy reached at a summit in Lisbon in November 2010, the coalition forces will gradually shift to a training, advisory and assistance role with the Afghan military on the way to withdrawing all combat troops by the end of 2014. NATO hasn't yet agreed on the pace of that process.

A Panetta spokesman traveling with the defense chief issued a statement later Wednesday, saying the US troops could still be involved in at least some combat operations in partnership with Afghan forces in 2014.

Panetta's comments about an accelerated change in the US mission in Afghanistan were the latest sign that the US and its NATO allies are seeking to hasten the end of their involvement in the unpopular war, said the Post.

In Brussels, NATO defense ministers discussed on Thursday the US plans to end combat operations in Afghanistan in 2013 and a shift in the role of its troops there. The meeting was held after French President Nicolas Sarkozy announced on Jan 27 that France would speed up its combat drawdown in Afghanistan this year.