The two leaders of the Senate Intelligence Committee sent letters to the 21 states reportedly targeted by Russian hackers during the 2016 election.

"This week the chairman and I sent a letter to all relevant state election officials asking that this information be made public," Vice Chairman Sen. Mark Warner, D-Va., said Wednesday during a committee hearing on Russian meddling in European elections.

He added in his opening statement: "I do not see how Americans are made safer when they do not know which state election systems Russia tried to hack."

An official from the Department of Homeland Security revealed last week Russian hackers targeted the election systems of 21 states during the 2016 presidential election.

DHS cybersecurity official Jeanette Manfra said the department discovered in early October "that Internet-connected election-related networks, including websites, in 21 states were potentially targeted by Russian government cyber actors."

Hoewever, Manfra said there was no evidence that votes were actually changed.

Only Arizona and Illinois have publicly said their systems were targeted.

During her testimony before the Senate Intelligence Committee last week, Manfra also said DHS continues to keep private the names of the other states affected to "protect the confidentiality that we have and the the trust that we have."

Warner at that time said he and Chairman Sen. Richard Burr, R-N.C., would send a letter to the other 19 states asking them to go public.