WASHINGTON (Reuters) - U.S. Defense Secretary Jim Mattis said on Thursday he believed President Donald Trump wants Washington, D.C., to be the setting for a parade to honor the U.S. military but left open the possibility that it could be staged elsewhere.

Trump has asked the Pentagon to explore a parade in celebration of American troops, after the Republican president marveled at the Bastille Day military parade he attended in Paris last year.

But critics have lampooned the proposal. They argue that a parade could cost millions of dollars and disrupt city streets and question why a show of military might is needed now.

Mattis, speaking to reporters, explained that he would give Trump options on the parade.

“We’ll work out everything from size, to participation to costs. And when I get clear options, we will send those over to the White House and I’ll go over and talk to them,” Mattis said.

When asked whether location was also a variable, Mattis suggested he had not yet considered alternatives to Washington but did not rule out other options, either.

“As I understand it, he wants the parade in Washington, D.C., but that’s a good question. I’ll see what we put together for options,” Mattis said.

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At least two congressional Democrats said they would introduce bills to block federal funding from being used for a military parade.

“First and foremost, diverting millions of dollars away from training our troops and supporting our military, especially at a time when Congress is struggling to pass annual appropriations, should be enough to kill this idea,” said Senator Ben Cardin, the top Democrat on the foreign relations panel.

On Wednesday, the Council of the District of Columbia ridiculed the idea of a parade on Pennsylvania Avenue, the 1.2-mile (1.9-km) stretch between the Capitol and the White House that is also the site of the Trump International Hotel.

“Tanks but no tanks!” it tweeted.

The Pentagon earlier on Thursday said it was not certain that the Washington area would host the parade.

“We don’t know that. There are options and we will explore those and the president will ultimately decide,” said Pentagon spokeswoman Dana White, adding that the U.S. Army was taking the lead in creating options for the event.

One possibility is for a parade on Nov. 11, the 100th anniversary of the end of World War One.