Members of the Kennedy family, one of America’s most famous political dynasties, have filed ‌to join a court case aimed at stopping construction of President Donald Trump’s proposed triumphal arch in Washington DC.

The Kennedys say the proposed 76-metre so-called “Arc de Trump” would obstruct views and cast ‌shadows over their relatives’ grave sites, including that of assassinated former president John F Kennedy.

The arch, shown in an official rendering to include a flame held by a 18.5-metre gold-winged female figure and flanked by gold flying eagles, would be across the Potomac River from ‌the Lincoln Memorial ‌on ⁠a highway roundabout near the entrance to the Arlington ​National Cemetery.

A judge has already issued a temporary order blocking construction until November 19 as she considers whether to issue a preliminary injunction.

The court filing claims the arch “will permanently cast shadows over and damage historically significant sight lines to the existing grave ⁠sites and memorials established in the Kennedy ‌family’s ​honour at Arlington National Cemetery, as well as to the memorials of hundreds ​of thousands of ‌fallen American heroes”.

The Kennedy family is ​the most prominent political dynasty in US history. Trump’s Health Secretary is Robert F Kennedy junior – JFK’s nephew. Kennedy jr’s father, then-senator Robert F Kennedy, was also assassinated.

RFK jr is not part of the arch lawsuit. The plaintiffs involved include seven of his siblings, who are the children of Robert and Ethel Kennedy. It also includes Robert and Ethel’s grandson – former Democrat congressman Joe Kennedy – and Ted Kennedy’s son Edward Kennedy junior.

The White House said it was “unfortunate” that the Kennedys had joined litigation against an arch “intended to honour our heroes who rest in Arlington Cemetery”.

“The judiciary should not be abused to politicise a structure designed to unite our nation,” White House spokesman Davis R Ingle told the BBC.

“We will continue making the case for this beautiful and fitting monument and are confident we will be fully vindicated as this litigation proceeds.”

The Trump administration contends Congress approved the arch more than 100 years ago when it also authorised construction of a bridge across the Potomac River.

On Wednesday, Veterans Day in the US, Trump said the arch would be dedicated to the US military and those who served in its ranks.

“Soon we’re going to dedicate a magnificent triumphal arc to our veterans,” he said.

“That’s in honour of our great veterans and our great militaries. They’ve been waiting for it for 200 years.”

Plans for the arch include a website unveiled last week that declared it “an American vision finally realised” and said it would be called the United States Military Triumphal Arch.

“This will be the greatest and most beautiful triumphal arch, anywhere in the world,” the website says, underneath a photograph of Trump.

The site also features the word “Triumph” in gold cursive script recalling the typeface used at Trump’s Mar-a-Lago estate in Florida.

The site says the monument “will be Highly Secretive but, at the same time, a Top Level and Lethal structure, the likes of which has not been seen in this Country before”.

The arch’s plans call for its columns to store munitions and areas on the pedestal and observation deck to be set aside for a sniper’s nest. Its base would be designed to launch drones.

The website does not say how much the project will cost or how it will be paid for, although some estimates have reached as high as $US100 million ($A145 million).

It is just one of Trump’s efforts to remake the US capital. Others include a mammoth ballroom to replace the White House East Wing, the troubled renovation of the Lincoln Memorial Reflecting Pool and adding his name to the Kennedy Centre, a major Washington DC cultural institution named in honour of JFK.

Numerous Democrats in Congress have vowed to block construction of the Washington DC arch once ​they take control ⁠in January, after winning last week’s midterm elections.

-with AAP