The US Defense Department expressed concern on Thursday about China holding military exercises in the South China Sea, saying the move will further destabilize the situation in the disputed waters, Reuters reported.

“Conducting military exercises over disputed territory in the South China Sea is counterproductive to efforts at easing tensions and maintaining stability,” the department said in a statement.

“The military exercises are the latest in a long string of PRC actions to assert unlawful maritime claims and disadvantage its Southeast Asian neighbors in the South China Sea,” the statement also said, referring to the People’s Republic of China.