Twitter said it will reject all advertising from two Russian media organizations — Russia Today (RT) and Sputnik — following its investigation into Russia-led efforts to interfere with the 2016 U.S. presidential election.

However, both RT, Russia’s state-funded broadcaster, and government-controlled news agency Sputnik will be allowed to “remain organic users” on Twitter, the company said in a blog post Thursday. That means they’ll be able to keep tweeting from their accounts, as permitted by Twitter’s terms of service.

“We did not come to this decision lightly, and are taking this step now as part of our ongoing commitment to help protect the integrity of the user experience on Twitter,” the company said.

In a January 2017 report, U.S. intelligence agencies named both RT and Sputnik as “implementing state-sponsored Russian efforts to interfere with and disrupt the 2016 Presidential election,” according to Twitter. The company added that the decision does not apply to any other advertisers.

Social media’s role in influencing the U.S. election, which put Donald Trump in the White House, has been a hot-button topic in American politics. On Wednesday, Nov. 1, Twitter, Facebook and Google execs are scheduled to testify at a Senate Intelligence Committee hearing about Russia’s alleged meddling in the election.

Last month, Twitter disclosed that it had found about 200 accounts likely linked to state-sponsored Russian entities, and said it received $274,100 in U.S. ad revenue from RT. Facebook has disclosed that about 10 million U.S. users viewed some of the 3,000 targeted ads purchased by a group affiliated with the Russian government designed to sow political discord.

Twitter said it will donate the $1.9 million it estimates it has earned from RT global advertising since it became an advertiser in 2011 — including the $274,100 pegged to the 2016 election — to “support external research into the use of Twitter in civic engagement and elections, including use of malicious automation and misinformation, with an initial focus on elections and automation.”

In a editorial in response to Twitter’s announcement, RT said it “has never been involved in any illegal activity online” and that it “never pursued an agenda of influencing the U.S. election through any platforms, including Twitter.” The media organization said Twitter had urged RT to “spend big to take stand” on the social-media site for the 2016 U.S. elections, and added that the two companies held brainstorming meetings about election-related ad campaigns dating back to April 2016, which involved “senior marketing and news partnerships managers from Twitter.”

RT editor-in-chief Margarita Simonyan also tweeted a response referencing Twitter CEO Jack Dorsey, saying, “Hope @jack won’t forget to tell @congressdotgov how @Twitter pitched @RT_com to spend big $$s on US elex ad campaign.”

Twitter announced the ad ban for RT and Sputnik after reporting third-quarter 2017 earnings that beat Wall Street expectations. The company also said it may turn in its first-ever profitable quarter for Q4 2017 on a GAAP (generally accepted accounting principles) basis.