Washington DC - President Donald Trump's project to paint the Reflecting Pool by the Lincoln Memorial bright blue has become his latest remodeling effort in the US capital to be met with a lawsuit.

The Cultural Landscape Foundation filed suit against the Interior Department and National Park Service on Monday to stop the repainting of the pool on the National Mall.

The 2,000-foot Reflecting Pool was built in 1922-1923 and is a key Washington landmark.

Trump is having it resurfaced and repainted "American flag blue" to mark the 250th anniversary this summer of the signing of the Declaration of Independence.

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Work on the Reflecting Pool project, which the billionaire real estate mogul personally inspected last week, has already begun, and the lawsuit filed by the foundation is seeking to have it halted.

In its suit, the nonprofit said the dark color of the pool's basin "creates the sweeping mirror image of the Lincoln Memorial and the Washington Monument that millions of visitors experience every year."

"The dark grey, achromatic basin was not incidental to the design," it says. "It was the design."

The foundation accuses the administration of "altering the historic character of the Reflecting Pool without following Congressionally mandatory procedures."

It said the "desecration" of the Reflecting Pool is "part of a pattern" of remodeling projects by Trump that include the destruction of the East Wing of the White House to make way for a massive ballroom.

The ballroom project is also the subject of a legal battle.

Trump has also recently unveiled plans to build a huge arch in the nation's capital to mark the July 4th independence anniversary.

Since taking office, Trump has also paved over the Rose Garden lawn at the White House and plastered the Oval Office with gold decorations.