A Democratic candidate for the US House from Southern California admitted Friday that he is not “fluent” in Vietnamese, as he had previously claimed — one day after The Post revealed his embellishment.

Derek Tran, an employment attorney running to represent the Golden State’s 45th Congressional District, acknowledged to the Los Angeles Times that he speaks in “broken Vietnamese” and is not fluent.

A first-generation Vietnamese American, Tran told the outlet that he once had fluency as the child of refugees from Southeast Asia, but he now uses a translator “because I don’t want any of my messaging to get lost.”

The Post revealed on Thursday that Tran, 43, had been bringing an interpreter with him to several Vietnamese-language interviews and even a campaign event — despite having bragged about being “the only candidate that speaks fluent Vietnamese.”

Other interviews showed Tran inserting English words and phrases — like “communism,” “amazing” or “grocery” — when unable to come up with the Vietnamese equivalent.

Vietnamese is the third-most common household language among residents of the plurality-Asian 45th District, and around 7% of Tran’s would-be constituents cast ballots printed in the vernacular, the LA Times reported, citing research from the firm Political Data Inc.

The Democratic Congressional Campaign Committee (DCCC) had also described Tran as “a candidate fluent in Vietnamese,” with a spokesperson saying in a statement to The Post Thursday that he was “the pride and joy of Little Saigon,” a Vietnamese enclave in Orange County.

The spokesperson further characterized the scrutiny of Tran’s linguistic capability as one of many “bad faith attacks on the cultural heritage of the son of Vietnamese refugees” in the final weeks of his push to unseat GOP Rep. Michelle Steel.

Tran’s campaign seems to have no problem with “negative” messaging, however, since it published a directive on the candidate’s website encouraging it.

“From the ninth to sixth weeks prior to the November general election, voters should ONLY see negative communication on digital and streaming,” the webpage states. “Voters do not need to see any positive communications at this point in the race.”

The focus on outreach to “Vietnamese voters” is also a priority of the Tran campaign, according to its website, which discusses how the voting bloc is “hyper-concentrated in the cities of Garden Grove and Westminster.”

“Vietnamese women under the age of 45 who speak English are a priority audience,” one webpage reads.

“There’s going to be MAGA, far-right Vietnamese Republicans that, you know, we’re not going to change their mind,” Tran promised the Los Angeles Times. “But I have Trump supporters who are going to vote down-ballot Democrat for me.”

In addition to Tran’s work as an attorney, he and his wife own a pharmacy, which his campaign has referenced to court Republican-leaning small business owners, along with his years of service in the US Army.

Both Tran and Steel have used Vietnamese in their official campaign messaging.

The 45th District race is considered a key seat in the battle for control of the House Nov. 5.

The nonpartisan Cook Political Report rates the race between Steel and Tran as a “lean Republican” despite the district’s Partisan Voting Index of D +2

Reps for the DCCC and the Tran campaign did not immediately respond to a request for comment.