The Trump administration targeted another state Monday by asking Washington state to sequester ballots in next week’s election that it says could be cast by noncitizens.

The acting U.S. attorney in Washington, Neil Floyd, asked the Washington secretary of state to review a list of more than 400 registrants the Justice Department believes are noncitizens and sequester any ballots they cast.

“We have identified over 400 non-citizens who are registered to vote and have voted in multiple elections,” Floyd said in a news release Monday. “This is only the tip of the iceberg. We will continue to investigate and identify those who are committing crimes by voting illegally.”

The request came the same day the Trump administration suffered a legal setback in its push to separate thousands of ballots in California as it seeks to inject the federal government into tallying and certifying the 2026 election results.

NBC News first reported last week that the Justice Department was considering bringing more requests to states with mail elections that send mail ballots to all registered voters.

In a letter sent to Washington election officials that was shared with NBC News, the Justice Department gave the state 24 hours to review the list for citizenship records.

Washington, which has more than 5 million voters on its voter rolls, refused to share its unredacted voter rolls with the Justice Department this year. Floyd criticized the state for that, saying Monday that it made his work more time-consuming.

In an interview with conservative radio host Jason Rantz that was published Monday, Floyd said his office checked lists of permanent legal residents like green card holders against voter registration records in their search.

Washington Secretary of State Steve Hobbs’ office is reviewing the list, spokesperson Helen Smith said in an email, though Hobbs criticized the request in a statement.

“We take our responsibility to protect voter information seriously and will only respond to requests that follow due process. We saw what happened in California and don’t want Washingtonians to be harassed,” he said. “The timing of this request—one week before the General Election—is no doubt intended to cast unfounded suspicion on the results.”

Noncitizens do end up on the voter rolls sometimes, though relatively few vote, since it’s a crime with a paper trail and one that can incur serious penalties, including deportation. Newly naturalized citizens are frequently flagged as noncitizens in voting records, in large part because there is no comprehensive list of U.S. citizens.

The Justice Department said last week that it believed there were 20,000 noncitizens on California’s voter rolls. It gave California 48 hours to review the administration’s list and called on it to sequester their ballots. The Trump administration later sued, asking a federal court to keep the state from counting any of those ballots. An appeals court ruled Monday against the Trump administration, saying the Justice Department had not given the lower court a chance to review the administration’s claims.

Los Angeles County election officials said in a legal filing that the Justice Department’s list of suspected noncitizens appeared to come from old voting lists and included many apparent U.S. citizens whose registrations included places of birth in the U.S.

The administration has sought to involve itself in ballot counting in other ways.

Last week, the Trump administration — at President Donald Trump’s suggestion — sued Alaska over the candidacy of a Senate candidate with the same first and last name as the Republican incumbent, Dan Sullivan. The suit asks the court to block certification of the race unless the Republican senator wins re-election.

Election experts told NBC News last week that the Trump administration’s various election lawsuits are on shaky ground, because nothing in federal law gives the Justice Department the authority to intervene in election certification or ballot counting.