The federal government spent about double the usual amount on the Fourth of July celebration in the nation’s capital last year after President Trump rebranded the annual event, including a push for a military flyover and a display of armored vehicles on the Mall.

A report released Thursday by the nonpartisan Government Accountability Office found that the tab for the 2019 “Salute to America” cost more than $13 million, well above the $6 million to $7 million that had been spent in the previous three years.

The report says the additional cost was driven by the expense of transporting several military vehicles to the Mall and the additional security needed for Trump, who attended the event. The president also delivered a 47-minute speech at the Lincoln Memorial, praising Americans’ sacrifice and extolling U.S. military might. Abrams tanks and Bradley Fighting Vehicles were stationed on the Mall, while a B-2 bomber, F-22 fighter jets and other aircraft flew overhead.

Critics accused the president of transforming the traditionally nonpartisan celebration of the nation’s founding into a campaign rally. Others, including National Park Service officials, warned that the military hardware could damage the area around the Lincoln Memorial.

“The Government Accountability Office’s report confirms what we knew all along: the president was willing to spend millions of dollars of taxpayer funds — expenses that weren’t budgeted for and roughly doubled what was spent in previous years — to meet his extravagant demands,” Democratic Sens. Patrick J. Leahy (Vt.), Tom Udall (N.M.) and Chris Van Hollen (Md.) said in a joint statement. “And now, the Trump administration is at it again.”

The lawmakers, who requested the GAO report, said they have requested the watchdog agency determine what the costs will be for this year’s event, which will take place on the White House’s South Lawn and the Ellipse.

Trump administration officials defended their orchestration of last year’s event.

“Salute to America is not about politics, it’s about all Americans coming together to celebrate Independence Day, our great armed forces and their heroic sacrifices, which have preserved our freedoms for generations, and our amazing heritage,” White House spokesman Judd Deere said in an email.

“Because of President Trump, fireworks are returning to Mount Rushmore for the first time since 2009 to celebrate America’s birthday,” he added.

Warnings have been made about the Trump administration’s plans for this year’s celebration. The plans include a giant fireworks display for July 3 at Mount Rushmore, despite a 10-year ban on such shows because of the risk of wildfire posed to thousands of acres of forest land. Environmental officials have said toxic residue from the fireworks pose a pollution threat to the national memorial’s drinking water. Health experts have warned that the event will draw crowds that can easily spread the novel coronavirus.

Trump plans to attend the Mount Rushmore event and celebrate the actual holiday from the White House with scheduled events that include a military flyover.

In previous years, the Fourth of July celebrations in the nation’s capital have included massive fireworks displays on the Mall, along with a performance by the National Symphony Orchestra and other musicians on the West Lawn of the U.S. Capitol. The event draws hundreds of thousands of people and has been broadcast live on television since 1947.

This year, the concert will not be held live because of the coronavirus. Performances were pretaped without an audience and will be broadcast on PBS.

Deere said this year’s celebrations would have a “different look” that reflects concerns about the pandemic. The National Park Service is requiring any groups seeking permits to gather on the Mall on July 4 to provide a plan to address the coronavirus, according to two senior Interior officials who spoke on the condition of anonymity to discuss internal planning.

Interior officials, in response to the GAO report, praised last year’s event.

“President Trump’s Salute to America last year was an incredible celebration of our nation’s founding and appropriately honored the tremendous sacrifices made by our men and women in uniform,” Interior Department spokesman Ben Goldey said in a written statement. “Interior looks forward to hosting President Trump for a safe and spectacular firework display at Mount Rushmore and again for Salute to America this year.”

D.C. Mayor Muriel E. Bowser (D) has no say in what the government does on federal land but has said she would not issue any permits for July 4 parades in the District while the city is under coronavirus-related restrictions that prohibit large gatherings.

Juliet Eilperin contributed to this report.