Washington: With US tanks parked nearby, workers set up a red-carpeted stage for President Donald Trump's planned July Fourth speech, as critics accused him of hijacking a nonpartisan celebration of America's Independence Day.

Army soldiers with the 3rd Infantry Division, 1st Battalion, 64th Armored Regiment, move a Bradley Fighting Vehicle into place by the Lincoln Memorial. Credit:AP

Trump is billing his production on Washington's monument-lined National Mall as a tribute to the American armed forces, featuring fighter jet fly-overs, military music, an extended fireworks display and a presidential speech.

"Our July 4th Salute to America at the Lincoln Memorial is looking to be really big. It will be the show of a lifetime!" he wrote on Twitter on Wednesday.

But America's divisive politics threatened to overshadow what has traditionally been a nonpartisan national holiday.