LONDON - Britain will likely follow the United States in reducing troop levels in Afghanistan but it will continue to work with its government and the U.S. to protect the country's security, Britain's Defence Secretary Ben Wallace said.

"I expect if they (the U.S.) are reducing at some stage, we will come down," he told Sky News on Thursday.

The Pentagon said on Tuesday that President Donald Trump will sharply reduce the number of U.S. forces in Afghanistan from 4,500 to 2,500 by mid-January. 

(Reporting by Paul Sandle; Editing by Kate Holton) ((paul.sandle@thomsonreuters.com; +44 20 7542 6843; Reuters Messaging: paul.sandle.thomsonreuters.com@reuters.net))