Trump administration officials said Wednesday that Russia targeted election-related systems in 21 states leading up to the 2016 presidential election.

A Department of Homeland Security (DHS) official made the disclosure Wednesday during testimony before the Senate Intelligence Committee as part of its probe of Russia's interference in the election.

“We have evidence of election-related systems in 21 states that were targeted," said Jeanette Manfra, acting deputy under secretary for cybersecurity and communications at DHS’s National Protection and Programs Directorate.

ADVERTISEMENT

Officials would not disclose which states were targeted, emphasizing the need to protect the confidentiality of the states affected. Authorities have previously said that voter databases in Arizona and Illinois were breached by foreign-based hackers. It is also unclear whether any of the remaining state systems were successfully breached.

Manfra would not disclose what states had data "exfiltrated" from their systems when questioned by vice chair Sen. Mark Warner Mark Robert WarnerFBI director casts doubt on concerns over mail-in voting fraud Democrats call for declassifying election threats after briefing by Trump officials It's time to upgrade benefits MORE (D-Va.).

“I prefer not to go into those details in this forum," Manfra said.

She said that all of the "system owners" targeted within the states are aware that they were targeted and that any states that had data exfiltrated are also aware.

Officials maintain that the systems targeted were not involved in vote counting.

Later, Bill Priestap, assistant director of FBI’s counterintelligence division, said that there was no doubt Russia was behind the targeting effort. He said the FBI has ongoing investigations into the matter.

The committee met to explore the security of U.S. election systems as part of a broader investigation into Russian interference efforts.