Britain's defense secretary says thousands of troops will leave Afghanistan next year, a major reduction in U.K. forces there.

Britain has said 500 of its 9,500 troops in Afghanistan will be withdrawn this year, and all will be brought home by the end of 2014, when international troops are due to hand security over to Afghan forces.

But it has not announced exactly how many will come home in 2013.

Defense Secretary Philip Hammond said Sunday that he planned "a significant reduction in force numbers by the end of next year."

He told the BBC that "thousands, not hundreds" of troops would be withdrawn late in 2013, "but I would not expect it to be the majority of our forces."

Since 2001, 433 British troops have died in Afghanistan.