Twitter is exploring how to notify its users that they saw Russian propaganda during the 2016 election

Twitter is exploring ways to notify perhaps millions of users who viewed Russian propaganda during the 2016 U.S. presidential election, the company revealed Wednesday.

Appearing at an unrelated hearing in the Senate, the company’s director of public policy, Carlos Monje, said Twitter is “working to identify and inform individually the users who have been exposed to IRA accounts during the election” — referring to the Internet Research Agency, an online troll army with Kremlin ties.

Monje did not elaborate how Twitter would do that. He did not say, for example, if the company would alert users who saw tweets from Russian-controlled accounts or only those targeted with ads. Nor did he say if Twitter would alert users who viewed content generated by RT, a news service tied to the Russian government, which the company has recently banned from sponsoring tweets on the site.

Asked for additional details, a spokeswoman for Twitter declined to comment.

Still, Twitter’s announcement comes amid pressure from Capitol Hill urging the company to do more to battle Russian disinformation — on top of sharp criticism that it has failed to respond to lawmakers’ demands in a timely, complete way.

Earlier this month, for example, Twitter failed to meet a deadline to answer questions sent from members of Congress who are investigating the Kremlin’s efforts on social media. Twitter previously reported that it found roughly 2,700 accounts tied to the IRA. It also ran a number of ads during the 2016 election purchased by RT.

At the end of 2017, Democratic Sen. Richard Blumenthal also requested that Twitter — along with its two peers, Facebook and Google — notify all users who had unwittingly viewed Russian propaganda.

In response, Facebook introduced a disclosure portal in December — though it only works for a fraction of the 140 million users whose feeds included disinformation.

Google, meanwhile, said it cannot easily provide such a tool, an answer that drew a sharp rebuke from Blumenthal at the Wednesday hearing.

The lawmaker said he is “disappointed by Google’s written response,” explaining that “they essentially blew off my concerns by saying the nature of the platform make it diff to know who has viewed its content.”

This article originally appeared on Recode.net.