WASHINGTON — President Trump pledged Thursday to clean up the “filthy” reflection pool outside the Lincoln Memorial and paint it an “American-flag blue” color in anticipation of the nation’s 250th birthday this Independence Day.

Trump told reporters in the Oval Office that a friend from Germany had recently visited DC and been appalled by the disheveled state of the 2,000-foot-long pool.

“He said, ‘It’s filthy, dirty. The water is disgusting-looking. It’s not representative of the country,'” the president said at a separate event touting a deal with a pharmaceutical company to drive down drug prices.

Historical events such as Dr. Martin Luther King Jr.’s “I Have a Dream” speech have taken place there, as have countless political rallies and speeches.

Former President Richard Nixon also famously made an impromptu visit to the memorial to speak with anti-Vietnam War protestors in May 1970.

Trump had earlier posted a video announcement about the renovations on his Truth Social account, noting that the pool, built in 1922, had “leaked like a sieve for many years,” and that he and Interior Secretary Doug Burgum had personally inspected it recently with a Secret Service detail.

“I do a lot of this as president, and try to save money,” he noted, bragging that he’d driven the cost of the construction down to $1.5 million or $2 million, and it would be done “long before July 4.”

The project’s price tag was initially pegged at $300 million to replace costly granite stones lining the pool’s base — and take more than three years to complete.

Instead, the pool was drained and the granite has been scrubbed clean and will be topped with an “American-flag blue,” “industrial-grade, swimming pool topping,” Trump boasted.

“It’ll last for 40 or 50 years; there’ll be no leaks,” he added. “It’ll look gorgeous, beautiful. So it’s a story in business. … This is a much better job, for much less money.”

The project comes as the president is also eyeing the construction of a triumphal arch near Arlington National Cemetery, with recently released photos showing the massive 250-foot-tall structure.

Trump is also planning to build a gilded grand ballroom for $400 million next to the White House’s East Wing, but a federal judge recently halted that project.