A month after the Trump administration declared without evidence that thousands of noncitizens had illegally registered to vote in Nevada, officials with the Department of Homeland Security were unable to substantiate the claim.

The administration claimed to have identified 278,000 noncitizens registered to vote in four states, including an exact number of 15,903 in Nevada. But during a meeting last week with state election administrators, Homeland Security officials said they had identified just 185 potential noncitizens in the state so far, according to emails as well as recordings of the meeting obtained by The New York Times.

The federal officials said they were still considering 14,000 names for further review, according to one of the emails. In the virtual meeting, federal officials told Nevada that the nearly 16,000 they had originally identified represented “the ceiling” of potential noncitizens.

But the list the Homeland Security Department shared with Nevada is incomplete — it doesn’t even include names — and is nearly impossible to verify, according to files released by the secretary of state’s office. Nevada officials have requested more information, but the department has not yet offered it.

Unproven claims that large numbers of noncitizens have voted in elections have been at the core of President Trump’s political message and central to his justification to enact the SAVE America Act, which would require people to show proof of citizenship to register to vote in federal elections. Democrats and voting-rights advocates say the legislation is aimed at tipping the scales in this year’s midterm elections for Republicans, in part by making it more difficult for some eligible Americans to cast ballots, notably younger voters and people of color, who tend to vote for Democrats.

To determine that the Department of Homeland Security had not verified Mr. Trump’s accusations, The Times examined 16 emails as well as recordings of a video call obtained from the Nevada secretary of state’s office through a public records request.

At the time of Mr. Trump’s accusation, the department specified that it had found noncitizen voters registered in four states: Nevada, California, Pennsylvania and New Jersey. “We are releasing the results of a stunning investigation by the Department of Homeland Security,” Mr. Trump said, implying falsely that the government had found solid evidence.

The next day, Homeland Security Secretary Markwayne Mullin pointedly threatened local election officials with prison time if they did not comply with the administration’s efforts to change election policies.

Cisco Aguilar, the Nevada secretary of state, swiftly pushed back on the administration, as did election officials in California and Pennsylvania.

In the meeting last week, Homeland Security effectively admitted that its initial claim had not been substantiated. That prompted some pointed questions from Nevada, according to a video recording of the virtual meeting between the two agencies.

“So what you’re saying is the 15,000 number has not been vetted? Basically, it’s the number that you are starting with?” asked C. Murphy Hebert, the chief deputy in the Nevada secretary of state’s office.

“I probably wouldn’t use the sentence, ‘It hasn’t been vetted,’” replied Kimberley Vogt, an official with Homeland Security. “Because definitely we’ve done something with it to get down to 15,000. So I wouldn’t say that. But it hasn’t had a full manual review of each one.”

The Nevada contingent also asked if any of them were under investigation, given Mr. Mullin’s earlier threats.

“The Department of Homeland Security would not — does not — have the statutory authority to charge an election official,” said Heather Honey, an official with a history of making false claims about elections, adding that Nevada officials were “cooperating” and working in good faith. “We don’t do enforcement of those particular laws.”

The Times previously reported that letters from the department to the four states heavily caveated the findings that Mr. Trump had described in his televised address. The letters said “there may be as many as” to describe how many noncitizens the department had found, and offered no details on how it had arrived at the numbers. Officials in Nevada, Pennsylvania and California requested more information on the findings and methodology.

“Weeks after the president held a national, prime-time speech making sweeping claims regarding noncitizens and the security of our elections, D.H.S. representatives informed our office that the numbers that were provided to the public are preliminary and that there is not high enough confidence to be able to share the full data set with Nevada officials,” Mr. Aguilar said in a statement on Thursday. “The Secretary of State’s office will not risk disenfranchising eligible voters and ripping away their constitutional right to vote without the highest confidence of their ineligibility.”

New Jersey has found itself in a different position, after Gov. Mikie Sherrill announced that the state had found that roughly 6,600 noncitizens were improperly registered to vote between June 2023 and June 2024 because of a software error in the Motor Vehicle Commission’s system. But even that finding fell far below the 35,152 noncitizens that the Trump administration claimed it had found in the state.

In response to questions from The Times, a spokesman from the Department of Homeland Security said that Mr. Mullin’s letter to Nevada explicitly said that the department wanted to work collaboratively with the state to verify the identities of the full list of noncitizens. He reiterated the department’s claim that “there may be as many as 15,903” noncitizens.

During the meeting, Ms. Honey said the agency had used a copy of Nevada’s publicly available voter file from July 2025. She acknowledged that the voter file changes every day with deaths, naturalizations, moves and other life changes, and that some of the data might be out of date. She added that because public voter files do not include Social Security numbers or other indicators, the Homeland Security Department could not use its immigration database to check for eligibility.

The inflated Nevada number and the subsequent absence of significant findings offer yet another example of Mr. Trump’s making an outrageous claim of widespread election fraud without the evidence to support it. Since returning to office, the president has brought the full weight of the federal government to the task of investigating voter fraud and noncitizen voting, making the administration’s inability to find a smoking gun all the more striking.

In the past, Republican state officials eager to claim that widespread noncitizen voting was common repeatedly put out inflated numbers, only to revise those figures sharply downward.

The federal database, known as the SAVE system, has also mistakenly flagged U.S. citizens as noncitizens in several states that use it to examine voter rolls. For example, Iowa revised an initial estimate of more than 2,100 potential noncitizens on its voter rolls to 277 after further review.

Of those cases, 35 noncitizens cast ballots that were counted in the general election in 2024 out of more than 1.6 million ballots across the state.

Previous investigations have found minuscule numbers of noncitizens on the voter rolls. In March, Louisiana said it had identified 403 noncitizens registered to vote in the state out of a total voting pool of 2.96 million — about 0.01 percent — with 83 having voted in at least one election since the 1980s. In 2024, Georgia said it had identified 20 potential noncitizens on its rolls out of roughly eight million registered voters, or 0.00025 percent.

Texas’ initial report last October was that there were about 2,700 noncitizens on the rolls, which was still 0.01 percent of the state’s nearly 19 million registered voters. The total lowered even further when counties dug into the numbers.

Homeland Security Made a Big Claim About Noncitizen Voting. Now It Can’t Prove It.