WASHINGTON — Two Bradley armored vehicles rumbled into place on Wednesday in front of the Lincoln Memorial, to be joined later by two Abrams tanks parked nearby. Cranes were putting into place the scaffolding for Jumbotron screens. And workers raced to finish a red, white and blue stage where President Trump will preside over one of the most unusual Fourth of July celebrations the capital has known.

The audience for Mr. Trump’s speech will include thousands of troops assembled by the White House to create a made-for-television moment in which the nation’s commander in chief is surrounded by the forces that he leads.

Weather permitting, the traditional songs for each branch of the military will be played while their officers stand by the president’s side and a procession of aircraft, including Air Force One and the Blue Angels, roars through the skies overhead. Hundreds of guests, many of them handpicked by the Republican National Committee, will watch from bleachers in a V.I.P. section erected close to the podium.

“It will be the show of a lifetime!” the president posted Wednesday morning on Twitter.

But Mr. Trump’s decision to turn Washington’s annual Fourth of July celebration into a kind of Trump-branded rally for America has drawn criticism from Democrats, top representatives of the city government and many military officials who believe the president is using the troops and their gear as political props.