A top Democratic official is warning in newly blunt terms that the party cannot partner effectively with the Trump administration to fend off foreign cyberattacks because of the president’s professed doubts about Russian interference in the 2016 election.

“The president’s words and actions have made it difficult to develop a truly effective trust-based relationship with the Department of Homeland Security,” Tom Perez, the chairman of the Democratic National Committee, wrote in a letter Tuesday to Sen. Ron Wyden (D-Ore.), in response to a request for information about how the major national party committees were guarding against information warfare. 

“While we have contact with those in the administration, this president’s continued refusal to recognize the threat of foreign interference in our elections creates a barrier to true cooperation,” Perez said. Though he acknowledged the agency’s “dedicated career people,” the DNC chairman concluded, “this fundamental problem comes from the top.”

The comments underscore the extent to which election security has become a partisan issue, three years after Democratic emails were stolen by Russian hackers and released as part of a broader effort that intelligence officials and investigators working under special counsel Robert S. Mueller III concluded was aimed at tilting the election in Donald Trump’s favor. The warning from Perez is a sign of Democratic unease about whether government authorities — whose capabilities to detect and fend off cyberattacks far exceed those of the party — are committed to bringing these resources to bear, just over a year before the 2020 election.  

Homeland Security didn’t respond specifically to a question about how the president’s views shape the agency’s mandate. But Matt Masterson, senior cybersecurity adviser for DHS’s Cybersecurity and Infrastructure Security Agency, pointed in a statement to the unit’s “sustained outreach and communication with campaigns and political committees throughout this election cycle to ensure they have an overview of the threat landscape, the federal government’s role in election security and best practices for campaigns.”

Masterson said the agency, which grew out of a law enacted in November, has engaged with more than a dozen presidential campaigns.

Yet the topic has remained a delicate one within the White House. When she was homeland security secretary, Kirstjen Nielsen was advised to focus on other topics, such as immigration enforcement, in conversations with the president, as The Washington Post has previously reported. And Trump, who has described Mueller’s investigation as the “Russian hoax,” told ABC in June that he would consider accepting information on his political opponents from a foreign government, adding, “If I thought there was something wrong, I’d go maybe to the FBI, if I thought there was something wrong.” 

The White House did not respond to a request for comment for this report.

Trump’s skepticism about Russia’s well-documented election interference has at times been echoed by his advisers and family members. Jared Kushner, his son-in-law, in April dismissed Russian efforts as “buying some Facebook ads.”

Wyden’s letter, sent last month, asked the major national party committees to detail steps they had taken to protect themselves to help Congress assess vulnerabilities and plan legislation. Democrats, including Wyden, have put forward a raft of election security bills, some with bipartisan support, but they have been stymied by Republican leaders. 

The deadline for Wyden’s request passed on Friday. By Tuesday, the three Democratic committees — the DNC as well as the groups responsible for House and Senate campaigns — had responded. Their three Republican counterparts had not, and none responded to requests for comment about the letter.

All three Democratic committees said they had added staff and were abiding by more rigorous guidelines. 

In addition to its first-ever chief security officer, the DNC reported hires in areas ranging from combating disinformation to enhancing infrastructure security. Addressing an issue that has bedeviled parties as well as individual candidates, perhaps most notably Hillary Clinton, Perez specifically said it was “no longer appropriate for an organization to run their own mail server, their own file sharing server, or their own web server.”

The Democrats’ House campaign committee, which reported attempted intrusion ahead of the 2018 midterms, said it had doubled its IT staff in the previous two years but emphasized cost barriers for campaigns.  

A report released in May by the company SecurityScorecard suggested that digital security at the DNC lagged behind security at the RNC. 

The decision of whether to respond to Wyden’s request highlights a growing debate over how much to reveal about self-defense. Democratic presidential campaigns have kept mostly mum on the issue.

But former technology officers at the DNC as well as the RNC said the information sought by Wyden is vital to assessing threats and developing a common posture. 

“The committees have a responsibility to be forthcoming, just like a company does,” said Andrew Barkett, a former RNC chief technology officer. “If a company has had a breach, which both the RNC and DNC have had, that company has a responsibility to tell their customers what they’ve done to remedy it, with the customers in this case being the voters and donors.” 

Raffi Krikorian, a former DNC chief technology officer, said he is sympathetic to concerns about disclosure. But he also said the amount of money being spent by nation-state actors on cyberwarfare is enough to overcome any advantage gained from secrecy. 

Federal agencies such as DHS are better positioned than individual lawmakers to gather information and assess the threat environment, Krikorian said. But he echoed Perez’s concern, saying, “I do not trust that these agencies are well funded, nor do I trust that they will act correctly given that their boss’s incentives seem to be to not admit that the Russians are trying to do anything.”

The Cybersecurity and Infrastructure Security Agency says it lacks the authority to impose mandates on political organizations — for disclosures or any other type of action. Its services are voluntary.

Josh Dawsey, Ellen Nakashima and Shane Harris contributed to this report.