FILE PHOTO - Senator Mark Warner (D-VA) arrives for a closed senators-only Capitol Hill briefing on election security at the U.S. Capitol in Washington, U.S., August 22, 2018. REUTERS/Joshua Roberts

WASHINGTON (Reuters) - U.S. Senator Mark Warner told the Senate Select Committee on Intelligence on Wednesday that Congress will need to act to stop foreign bad actors who use social media like Facebook Inc FB.O and Twitter Inc TWTR.N to interfere in U.S. elections.

Warner, the top-ranking Democrat on the panel, said the companies’ efforts to address the problem were inadequate.

“The bad news, I’m afraid, is that there is a lot of work still to do. And I’m skeptical that, ultimately, you’ll be able to truly address this challenge on your own. Congress is going to have to take action here,” he said.

Top Facebook and Twitter executives were testifying at a committee hearing about foreign entities’ use of social media to influence U.S. political discourse.

Warner also said that he was deeply disappointed that Google did not send a top official to the hearing.