China has recently been pushing its presence in the energy-rich waters while other claimants are pre-occupied with tackling the new coronavirus pandemic, prompting the United States to call on China to stop its “bullying behaviour” there.

On Saturday it said it had established an administrative district on the Paracel islands and another on the Spratly islands.

The two districts are under the control of China’s Sansha city, according to China Global Television Network.

“The establishment of the so-called Sansha City and related activities seriously violated Vietnam’s sovereignty,” Vietnam’s Foreign Ministry spokeswoman Le Thi Thu Hang said in a statement.

“Vietnam demands that China respect Vietnam’s sovereignty and abolish its wrongful decisions,” Hang said in the statement.

A Chinese government survey ship was seen earlier this week tagging an exploration vessel operated by Malaysia’s state oil company Petronas in the disputed waters, and remained offshore of Malaysia as of late Sunday.

Earlier this month, Vietnam lodged an official protest with China after the sinking of a Vietnamese fishing boat it said had been rammed by a China Coast Guard vessel near the Paracels.