Biden honors outgoing Joint Chiefs of Staff Chairman Mark Milley

President Joe Biden honored outgoing Joint Chiefs of Staff Chairman Mark Milley at a ceremony Friday where the nation’s highest-ranking military officer handed the reins to his successor, Gen. Charles Q. Brown Jr.

The program, filled with pomp and circumstance, included Milley's swearing in Brown as the 21st chairman. Brown previously served as the Air Force chief of staff.

Biden topped his remarks with a tribute to Sen. Dianne Feinstein, D-Calif., whose office confirmed on Friday that she died at the age of 90.

"She was a historic figure, trailblazer for women, and a great friend. Dianne made her mark on everything from national security to the environment, gun safety to protecting civil liberties," Biden said. "The country is going to miss her dearly, and so will Jill and I."

Biden added that he would have more to say on the late California senator later Friday.

The president also addressed the looming government shutdown, saying that if the House fails to fund the government, it would be failing troops who would continue to show up for work despite not getting paid.

"It's a disgrace," he said, adding that the longer a shutdown lasts, the harder it becomes for military families to pay their bills.

"You can't be playing politics when our troops stand in the breach," Biden said. "It's an absolute dereliction of duty."

Vice President Kamala Harris and Secretary of Defense Lloyd Austin also attended the armed forces' farewell tribute to Milley.

“General Milley is a scholar and a warrior," Austin said. "We respect him for his wit, but we love him for his heart. And he’s thrown his whole heart into leading this tremendous joint force of soldiers, sailors, airmen, Marines, guardians.”

Milley was presented with his retirement certification, capping a more than four-decade career that included positions as Army chief of staff and commanding general of the U.S. Army Forces Command.

In remarks at the ceremony, Milley appeared to take a jab at former President Donald Trump, when he suggested the nation's armed forces took an oath to the Constitution rather than to a "wannabe dictator."

"We don't take an oath to a king, or queen, or to a tyrant, or a dictator, and we don't take an oath to a wannabe dictator," Milley said.

"We don't take an oath to an individual," he continued. "We take an oath to the Constitution, and we take an oath to the idea that is America and we're willing to die to protect it."

Trump last week took aim at the outgoing general, saying in a social media post that "in times gone by" Milley would have been executed for what the former president called "treasonous" conduct during the period after the 2020 election when Trump attempted to stay in power.

Milley's successor was confirmed this month in an 83-11 vote amid a standoff over military nominees initiated by Sen. Tommy Tuberville, R-Ala., who has blocked military promotions to protest a Defense Department abortion policy.

Biden strongly condemned the hold on the nominations during his remarks, calling it "thoroughly, totally unacceptable" and detrimental to readiness, morale and retention.

"I've been here a long time. I've never seen anything like this," Biden said. "It's outrageous."

Biden said that the military members whose promotions are stalled are having their futures "held hostage by the political agenda of one senator and the silence of another 47 of them."

"Our troops deserve so much better," he added later.

During his remarks, Austin also called on the Senate to "swiftly confirm all of our distinguished military nominees," which the audience responded with applause.

Biden had announced his intention to nominate Brown as chairman of the Joint Chiefs of Staff in May, calling him a "warrior, descended from a proud line of warriors."

This article was originally published on NBCNews.com