US defence secretary Chuck Hagel 'to step down'

Chuck Hagel has served less than two years as secretary of defence

Chuck Hagel will resign as US defence secretary after a request from President Barack Obama to step down, US media report.

Mr Hagel, 68, a Vietnam war veteran and former senator, became defence secretary in 2013.

He is reportedly stepping down amid a shift in US military strategy to fight Islamic State (IS), the New York Times first reported.

He is expected to stay on as secretary until his successor is confirmed,