WASHINGTON — A massive military parade unfolding against the backdrop of President Donald Trump’s unconventional flex of fighting forces in American streets this week was on track to begin Saturday evening with tanks, bands and thousands of troops.

The parade, honoring the Army’s long-planned 250th anniversary celebration and coinciding with Trump’s 79th birthday, was set to step off from the Lincoln Memorial under the threat of stormy weather in Washington and the potential for protests around the country tied to a turbulent week of immigration enforcement that has involved military deployment in Los Angeles.

Trump has brushed off the possibility of both disruptions, with a social media post Saturday morning that said the “great military parade” would be on “rain or shine.” The protests, he said earlier, “will be met with very big force.”

Hours ahead of the parade, crowds of protesters with anti-Trump signs marched toward the White House, escorted by police vehicles and officers on bicycles. Some held a giant banner that read “TRUMP MUST GO NOW.”

Added just a few weeks ago to the Army’s birthday celebration, the parade has triggered criticism for its price tag of up to $45 million and the possibility that the lumbering tanks could tear up city streets. The Army has taken a variety of steps to protect the streets, including laying metal plates down along the route.

About 6 in 10 Americans say Saturday’s parade is “not a good use” of government money, including the vast majority of people, 78%, who neither approve nor disapprove of the parade overall, according to a poll from Associated Press-NORC Center for Public Affairs Research.

The daylong display of America’s Army comes as Trump has shown his willingness to use the nation’s military might in ways other U.S. presidents have typically avoided, inviting an array of lawsuits and accusations that he is politicizing the military. In the last week, he has activated the California National Guard without the governor’s permission and dispatched the U.S. Marines to provide security during Los Angeles protests related to immigration raids, prompting a state lawsuit to stop the deployments.

He similarly sought to project military strength during his first presidential term, saying in 2020 that he wanted forces to “dominate” the streets following racial justice protests that turned violent and warning governors that he was prepared to send in active-duty fighters if they did not call out the National Guard in their states.

Earlier last week, Trump raised eyebrows during a speech at Fort Bragg when members of the 82nd Airborne Division were directed to stand behind Trump and they booed and cheered during his incendiary remarks, including condemnation of his predecessor, Joe Biden. There also was a pop-up “Make America Great Again” merchandise stand nearby selling souvenirs to troops in uniform.

The Defense Department has a doctrine that prohibits troops from participating in political activity while in uniform. Members of Congress and military leaders have expressed concerns about the political displays during the speech at Fort Bragg.

The parade fulfills Trump’s expressed desire for a big parade that he tried to get done in his first term after seeing one in France on Bastille Day in 2017. Trump said that after watching the two-hour procession along the famed Champs-Élysées, he wanted an even grander one on Pennsylvania Avenue.

Saturday’s event is expected to include about 6,600 soldiers, 50 helicopters and 60-ton M1 Abrams battle tanks, as well as possibly 200,000 attendees and heightened security to match.

The parade will wind down Constitution Avenue, which is already lined with security fencing and barriers.

Army helicopters and aircraft will fly above, and the march will be capped off by a parachute jump, a concert featuring “God Bless the U.S.A.” singer Lee Greenwood and fireworks.

Hours before the parade was scheduled to start, vendors set up shop on along Pennsylvania Avenue in anticipation of the expected large crowds. Large snowplows blocked off vehicle traffic, allowing pedestrians to walk on the historic street and visit vendors selling art, souvenirs, clothes, jewelry, beverages and food including funnel cakes and lobster rolls.

A daylong festival features fitness competitions, demonstrations, equipment displays, music and a cake-cutting ceremony. A line to enter stretched nearly half a block, with attendees sporting apparel celebrating both the Army and Trump.

Outside the festival gates, a large video board promoted careers in the Army, urging onlookers to consider enlistment.

It remained unclear whether any protests might disrupt the parade, though several hundred assembled in the hours before.

Officials have said they have no indication of any security threat.

“No Kings” rallies — organizers picked the name to support democracy and speak out against what they call the authoritarian actions of the Trump administration — planned in hundreds of cities nationwide are meant to counter what organizers say are Trump’s plans to feed his ego on his 79th birthday and Flag Day.

At the end of the parade, Trump was scheduled to swear in 250 new or reenlisting troops, and the Army’s Golden Knights parachute team was to jump onto the Mall, followed by the concert and fireworks.