Key Democratic lawmakers urged Republican leadership Wednesday to include additional FBI funding in the fiscal 2018 spending bill to combat possible Russian interference in the upcoming midterm elections.

The request comes after the Justice Department charged 13 Russian nationals and three Russian companies Friday over alleged attempts to interfere with the 2016 presidential election.

Senate Minority Leader Charles E. Schumer and House Minority Leader Nancy Pelosi, along with Rep. Nita M. Lowey of New York and Sen. Patrick J. Leahy of Vermont, the top Democrats on the House and Senate Appropriations Committee, respectively, are seeking an additional $300 million increase in funding for the FBI in the coming omnibus.

“This additional funding should be targeted to ensure the resources and manpower to counter the influence of hostile foreign actors operating in the U.S., especially Russian operatives operating on our social media platforms,” the Democratic lawmakers wrote in a letter to Senate Majority Leader Mitch McConnell and House Speaker Paul D. Ryan.

Top administration officials acknowledged Russian interference in the 2016 presidential election and warned of possible similar interference in this year’s midterms.

Several lawmakers, including Sens. Chris Van Hollen of Maryland and Marco Rubio of Florida, have introduced various bills intended to deter Russian tampering in the elections.

In a separate letter, Schumer also urged Director of National Intelligence Dan Coats and Department of Homeland Security Secretary Kirstjen Nielsen to make public the ways in which Russia is attempting to influence the 2018 elections. That letter was signed by Van Hollen and Democratic Sens. Richard J. Durbin of Illinois, Amy Klobuchar of Minnesota, Jack Reed of Rhode Island and Dianne Feinstein of California.

“We strongly urge you to release a public report identifying how Russia is working to interfere in the 2018 elections and to provide a classified appendix to relevant Senate and House Committees as well as state election officials with the proper clearances,” the lawmakers wrote. “The least we can do is ensure that state election officials — the people on the front lines of our democratic process — have the information they need to combat threats. This is vital to protecting our national security against cyberattacks.”

Watch: Intelligence Officials Aware of Russian Activity Aimed at 2018 Elections