The divided US capital epitomized a political rift in the United States that Saturday's display of soldiers, tanks and fighter jets looked to further deepen.

For Shaun Dailey, who traveled from neighboring Pennsylvania, the parade was simply a chance to honor the US Army on its birthday, which coincided with Trump's 79th.

"Some of them say that, 'Oh, it looks like North Korea. Oh, it looks like Russia,' because America doesn't do very many military parades. I don't know, because we're told to be ashamed of who we are," the 22-year-old said.

"But I personally don't see that as authoritarian. I don't see it as fascist or whatever. I just see it as a celebration."

Brent Kuykendall, 66, who flew from Texas with his wife to see the parade, agreed that it was a form of "patriotism."

"It's more than Trump. It's to celebrate our country," said Kuykendall, who carried a bag styled with US flags.

But many in liberal Washington were uneasy with the huge military display that has seen much of the downtown area shut down by roadblocks.

Secret Service agents, some with sniffer dogs, prowled the entry points to the National Mall area where the parade was taking place Saturday.

The White House -- typically visible for tourists behind a single metal fence -- was cordoned off with a large black barrier reading "Do not enter."

- 'Military as pawns' -

A few hundred protesters marched to the perimeter to voice their opposition to the military parade -- and Trump's second presidency.

"I flew in to oppose Trump's fascist birthday parade," said Sam Richards, a US army veteran from Minneapolis, some 1,000 miles from Washington.

"All of this feels like a cruel joke, to use people that swore an oath to the Constitution and are devoting their lives to the military as pawns for a guy who wants to be a king," Richards, 34, said.

He was surrounded by activists who held signs reading "Pro USA, anti Trump" and "Americans will not be ruled."

There was also a wooden model where protesters had gathered earlier depicting Trump with an elongated nose, sitting on a toilet with suit trousers around his ankles.

Organizers emphasized the rally should be nonviolent -- but some were still wary of Trump's promise last week that anyone trying to derail the military parade would be met by "heavy force."

"It's very important to stand out here today because there's so many people that are afraid," said Anahi Rivas-Rodriguez, 24, who is from Washington.

She acknowledged she felt "intimidated" by comments made by the president.

"But that does not stop me, because protesting is patriotic."

The Washington protest was among hundreds of rallies taking place across the United States on Saturday, including New York City and Los Angeles.

Bill Kennedy, 68, traveled to the capital from neighboring Pennsylvania as he believed it was crucial to display opposition to Trump.

"I think he needs to see that. You know, he's not going to get away with intimidation, threats, violence and thuggery, that people will still be opposed no matter what," he said.