In a letter released Thursday, Rep. Jerrold Nadler, D-N.Y., questioned the Trump administration’s commitment to election security and pressed administration officials to communicate more clearly with Congress about the issue.

A pair of U.S. senators wrote to the heads of the Department of Homeland Security (DHS) and Federal Bureau of Investigation (FBI) on Friday, imploring them to work with social media companies to root out election interference on their platforms and asking the agency heads for more information on the steps they’ve already taken to do so.