Former Homeland Security Secretary Jeh Johnson says the Russian government at President Vladimir Putin's direction clearly conducted cyberattacks on the United States to influence the presidential election, but the assault did not change ballots, the final count or the reporting of election results.

In prepared testimony, Johnson described the steps he took once he learned of the hacking of the Democratic National Committee, his fears about a cyberattack on the election itself and his rationale for designating U.S. election systems, including polling places and voter registration databases, as critical infrastructure in early January — two weeks before President Donald Trump's inauguration.

Johnson, who worked for Democratic President Barack Obama, is slated to testify on Wednesday before the House intelligence committee, which is investigating Russian meddling in the election and possible collusion with the Trump campaign. The Senate intelligence committee plans a hearing on the same election issues with current FBI, homeland security and state election officials.

"In 2016 the Russian government, at the direction of Vladimir Putin himself, orchestrated cyberattacks on our nation for the purpose of influencing our election - plain and simple," said Johnson, who warned that cyberattacks would get worse before they get better.

Johnson described his discussions with state election officials about ensuring the integrity of the voting process. He said 33 states and 36 cities and counties used his department's tools to scan for potential vulnerabilities.

He also said he contacted The Associated Press, which counts votes, and its CEO, Gary Pruitt.

"Prior to Election Day, I also personally reviewed with the CEO of The Associated Press its long-standing election-day reporting process, including the redundancies and safeguards in its systems," Johnson said.

In the end, the former homeland security chief said, "To my current knowledge, the Russian government did not through any cyber intrusion alter ballots, ballot counts or reporting of election results. I am not in a position to know whether the successful Russian government-directed hacks of the DNC and elsewhere did in fact alter public opinion and thereby alter the outcome of the presidential election."

Johnson served as Obama's homeland security chief from December 2013 to January 2017.

The Senate intelligence committee, which also is examining Moscow's interference in the campaign, is holding a separate hearing Wednesday with officials from DHS and the FBI's counterintelligence division. Special counsel Robert Mueller is conducting an inquiry into possible collusion between the Trump campaign and Russian officials.

Trump has decried the probes as witch hunts and he's rejected the U.S. intelligence community's assessment that Russia's hacking and disinformation campaign was intended to aid his candidacy.

Johnson's designation of U.S. election systems as critical infrastructure was aimed at providing more federal cybersecurity assistance to state and local governments to keep voting safe from tampering.

Johnson announced the shift on the same day as the release of a declassified U.S. intelligence report that said Putin "ordered" an influence campaign in 2016 aimed at the U.S. presidential election. The report said Russian intelligence services had "obtained and maintained access to elements of multiple U.S. state or local electoral boards."

None of the systems targeted or compromised was involved in vote tallying, the report said, and there's no indication Russia's prying changed vote counts in key states.

But Johnson's decision triggered an outcry from state and federal election organization officials. They complained that Johnson's department failed to respond to questions and concerns they had about the designation before the change was made.

American elections are highly decentralized. Voters cast ballots in roughly 185,000 precincts spread over 9,000 jurisdictions during the 2016 presidential election. Elections are also subject to rigorous and elaborate rules that govern how and what equipment is used.