U.S. President Donald Trump will preside over July Fourth Independence Day celebrations on Thursday with a speech about patriotism and a show of military might that critics say is politicizing an important holiday and wasting taxpayer money.

Trump, a Republican who admired flashy displays of national pride and military strength put on by France, has dismissed concerns about the expense and militaristic overtones of the Washington event, which will take place in front of the Lincoln Memorial and feature fireworks, a flyover by Air Force One and a display of tanks.

Democrats charge the president with staging a campaign rally. Though the White House has said his remarks would not be political in nature, the president has a history of veering off script with sharp partisan attacks even at events that are not meant to be overtly political.

"We're going to have a great Fourth of July in Washington, D.C. It'll be like no other," Trump told reporters earlier this week in the Oval Office. Asked if he could give a speech that would represent all Americans, he said he thought he could and then launched into an attack on Democrats' policies on healthcare and taxes.

Flights will be suspended at nearby Reagan National Airport from 6:15 p.m. to 7:45 p.m. ET and then again later in the evening for the festivities.

Republican political groups were given prime tickets for Trump's speech, and the Washington Post reported that the U.S. National Park Service diverted $2.5 million in park entrance fees to help pay for the event.

"Instead of addressing something like veteran homelessness, he's spending it on boosting his ego with a parade that's fundamentally about him and then getting tickets in the hands of wealthy donors for the Republican Party. What a waste of money," Democratic presidential candidate Julian Castro said on CBS "This Morning" on Wednesday.

Fellow Democratic presidential candidate Senator Bernie Sanders also weighed in with criticism: "This is what authoritarians do: @realDonaldTrump is taking $2.5 million away from our National Park Service to glorify himself with a spectacle of military tanks rolling through Washington," he wrote in a tweet.

Trump downplayed the expense.

"The cost of our great Salute to America tomorrow will be very little compared to what it is worth. We own the planes, we have the pilots, the airport is right next door (Andrews), all we need is the fuel," he posted on Twitter on Wednesday. "We own the tanks and all. Fireworks are donated by two of the greats. Nice!" Andrews is the name of a nearby military base.

The July 4th holiday celebrates the anniversary of U.S. founders' declaring independence from Britain in 1776.