Obama says US concerned over China 'using muscle' in 'disputed' South China Sea

U.S. President Barack Obama has voiced concerns over China using "sheer size and muscle" to intimidate smaller nations in the row over the South China Sea.

The statement came as focus intensified on Beijing's construction of artificial islands in disputed areas of the sea, reported the BBC.

On Thursday, a U.S. think tank released images of land reclamation work being carried out on a reef claimed by the Philippines. China said that the work was needed to safeguard its sovereignty.

The South China Sea is the subject of territorial claims with China, Brunei, Malaysia, the Philippines, Taiwan and Vietnam disputing sovereignty of several island chains and nearby waters.

China has consistently resorted to history to stake territorial claims in the sea and objects to "U.S. interference."

The U.S. is not a claimant of territory in the South China Sea but says it has a national interest in the peaceful resolution of the conflict for world trade.