US defence chief visits aircraft carrier in S. China Sea

US Defence Secretary Ashton Carter visited an aircraft carrier in the South China Sea on Thursday, amid rising tensions over Chinese sovereignty claims in the disputed waterway.

"There's a lot of concern about Chinese behaviour out here," Carter said during his three-hour visit to the USS Theodore Roosevelt.

He called the ship's presence "a sign of the critical role that United States military power plays in what is a very consequential region for the American future".