WASHINGTON — President Trump celebrated on Thursday after a federal judge gave the green light to continue building his ambitious $400 million White House ballroom project.

US District Judge Richard Leon, appointed by George W. Bush, determined that the construction of this major endeavor did not breach federal law, countering claims made by the National Trust for Historic Preservation.

“Fantastic news for America and our magnificent White House! The judge in the case concerning what will be the most stunning ballroom in the world has just dismissed and completely nullified the attempt to halt its construction,” Trump announced enthusiastically on Truth Social.

However, Judge Leon noted that the National Trust might revise its lawsuit and pursue the case under a different legal approach.

“The construction of the ballroom, expected to accommodate future inaugurations and significant state visits, is progressing ahead of schedule and under budget. It will endure through the ages as a testament to the greatness of America!” Trump added.

The planned 90,000-square-foot ballroom is set to surpass the size of the current White House and is being erected where the East Wing once stood.

The ritzy venue is intended to be “impenetrable” with “drone-proof ceilings” and bullet-proof glass, according to Trump. Beneath it, the administration is speculated to be renovating the White House nuclear bunker.

Late last year, the National Trust for Historic Preservation, which Congress has entrusted with preserving historic buildings, sued to stop construction of the ballroom on the grounds that Trump didn’t comply with federal guidelines.

Specifically, the preservation group argued that the Trump administration violated the Administrative Procedure Act, which requires federal agencies to follow certain guidelines and inform the public about certain actions.

But ultimately, Leon argued that a violation wouldn’t apply because the White House Office of the Executive Residence, which is overseeing the ballroom project, isn’t a federal agency.

“Unfortunately for Plaintiff, its challenge fails because the White House office in question is not an ‘agency’ under the APA,” Leon wrote in his opinion.

The jurist said the National Trust failed to prove that the president acted beyond his authority.

Trump has collected private donations to fund the ballroom project.

Just last week, DC’s Commission on Fine Arts, whose members Trump selected himself after booting the old panel, unanimously voted to approve his ritzy ballroom project.

The president still needs to get the go-ahead from the National Capital Planning Commission, headed by White House staff secretary William Scharf, which is set to meet on March 5.