ON BOARD USS THEODORE ROOSEVELT (AFP) - United States Defence Secretary Ashton Carter visited an aircraft carrier in the South China Sea on Thursday (Nov 5), amid rising tensions over Chinese sovereignty claims in the disputed waterway.

"There's a lot of concern about Chinese behaviour out here," Mr 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".

The move comes with Washington and Beijing engaged in a big-power face-off over Chinese assertions of sovereignty over virtually the entire South China Sea and its construction of islands via land reclamation to reinforce its claims.

Last week, Washington sent the guided missile destroyer USS Lassen to within 12 nautical miles of at least one of those man-made islands in the Spratlys chain.

The move, which angered China, was intended to press Washington's right to freedom of passage through the area.

The enormous, nuclear-powered USS Theodore Roosevelt was located between 150 and 200 nautical miles south of the Spratly islands at the time of Carter's visit.

It was accompanied by the USS Lassen, but US officials have stressed that the aircraft carrier was on a routine transit of the South China Sea, and was not there to press the freedom of navigation issue.