(Reuters) - U.S. officials are seeking to block an undersea cable between Los Angeles and Hong Kong, backed by Alphabet Inc's Google GOOGL.O, Facebook Inc FB.O and a Chinese partner, over national-security concerns, the Wall Street Journal reported on Wednesday.

The Justice Department has signaled staunch opposition to the project because of concerns over its Chinese investor, Dr. Peng Telecom & Media Group Co, and the direct link that the cable would provide to Hong Kong, the WSJ reported, citing people involved in the discussion.

“DOJ does not comment on its ongoing assessment of applications that the FCC has referred for national security and law enforcement concerns arising out of foreign investment or control,” said Marc Raimondi, a national security spokesman for the U.S. Department of Justice.

Google, Facebook and Dr. Peng did not respond to Reuters’ requests for comment.

Subsea cables form the backbone of the internet by carrying 99% of the world’s data traffic.