WASHINGTON — Sen. Amy Klobuchar on Tuesday called for a classified briefing for senators on Russian attempts to breach American voting systems.

Citing reports that the Russian military launched a cyberattack on a U.S. supplier of voting software and the e-mail accounts of more than 100 local voting officials around the U.S., Klobuchar voiced concern that the revelations went far beyond those laid out in a December report from domestic intelligence agencies about the extent of Russian election interference.

"It is vital that we have all of the information necessary to ensure that future elections are safeguarded from foreign interference," Klobuchar wrote to National Security Advisor H.R. McMaster. She requested a briefing "on the full extent of Russian interference in U.S. election systems" for the Senate Committee on Rules and Administration, of which she is ranking member.

Additionally, Klobuchar requested the public release of information that could make election systems safer from similar attacks.

"Free and fair elections are the cornerstone of our democracy ... We cannot let this happen going forward and need all the information available about Russia's attack as soon as possible," Klobuchar wrote.

Early this year, Klobuchar called for a full account of the Election Assistance Commission's efforts to address Russian cybersecurity threats, and also visited Ukraine, the Baltic states and the nation of Georgia to examine international cybersecurity threats with Republican Sens. John McCain of Arizona and Sen. Lindsey Graham of South Carolina.

The Senate Judiciary Committee, with Klobuchar as a member, is one of several Congressional panels investigating Russia's attempts to meddle in the 2016 U.S. election.

Maya Rao • 202-662-7433