A senator investigating Russia's role in the 2016 election wants to see social media companies make changes to ads to limit foreign influence in the future.

Senate Intelligence Committee Vice Chairman Sen. Mark Warner, D-Va., said platforms such as Facebook are starting to recognize the threat posed by nefarious use of social media. Divisive Facebook ads believed to be linked to Russia targeted specific parts of the United States last year, including states considered to be battlegrounds, according to NBC News.

Warner said he wants top social media companies to make three tweaks to address the problems created by foreign-linked ads. He specifically named Facebook, Google and Twitter.

He wants Americans seeing an ad to "know whether the source of that ad was generated by foreign entities."

Warner said users should know if a trending story is appearing because real users like it. Bots or false accounts — sometimes used by foreign intelligence services — could also make news appear as trending, he said.

The senator wants campaigns to be able to see social media ads run for or against them, as they can with television and radio ads.

Warner made the comments as he and committee Chairman Sen. Richard Burr, R-N.C., updated reporters on the investigation into Russian efforts to influence the election and possible Trump campaign collusion with the Kremlin. The senators said they believe Moscow will keep trying to affect U.S. elections. Such an effort could use social media.

The intelligence committee's staff has already interviewed representatives from Facebook. The company has turned over more than 3,000 ads believed to be linked to the Kremlin.

Senators have invited Facebook, Google and Twitter officials to testify at a hearing on Nov. 1, Burr said. They expect company officials to attend.

Warner and Sen. Amy Klobuchar, D-Minn., have said they are working on legislation to make political ads more transparent on social media. It would require companies to take more steps to ensure that foreign nationals do not directly or indirectly purchase political ads.