The United States is tightening controls on Chinese imports of civil nuclear technology to prevent its use for military or other unauthorized purposes, the U.S. Department of Energy said on Thursday.

The policy comes amid escalating trade tensions between Washington and Beijing. Last month, U.S. President Donald Trump imposed tariffs on nearly $200 billion of Chinese imports and then threatened more levies if China retaliated. China then hit back with tariffs on $60 billion of U.S. imports.

"The United States cannot ignore the national security implications of China's efforts to obtain nuclear technology outside of established processes of U.S.-China civil nuclear cooperation," U.S. Secretary of Energy Rick Perry said in a statement.