The US has described new Chinese rules on fishing access to disputed areas of the South China Sea as “provocative and potentially dangerous”.
Regulations approved by Hainan province requiring foreign fishing vessels to ask for permission to enter its waters took effect on 1 January.
China claims a U-shaped swathe of the South China Sea, which it puts under the authority of Hainan province.
This swathe overlaps areas also claimed by several South East Asian nations.
The move comes with tensions already high over China’s recent establishment of an Air Defence Identification Zone (ADIZ) that covers East China Sea islands claimed and controlled by Japan, and a rock claimed by South Korea.