A US army sentinel guarding the Tomb of the Unknown Soldier loudly reprimanded the embattled US defense secretary, Pete Hegseth, and his top staffers on Wednesday, after some in the group were heard laughing and talking near the memorial following a Veterans Day ceremony.

According to video captured by the TV network pool, Hegseth was with his wife, Jennifer, chief of staff Ricky Buria, deputy chief of staff Patrick Weaver and senior adviser and deputy assistant Tami Radabaugh walking up the steps in front of the memorial after posing for pictures. A laugh is audible, prompting the guard to yell: “All visitors will maintain an atmosphere of silence and respect at all times.” Hegseth looked over his shoulder in the direction of the soldier as he continued walking up the steps.

Chief Pentagon spokesman Sean Parnell said in a statement: “The secretary and the entire department have always honored – and will always honor – the sacrifices our military men and women have made to keep America safe.

“While commemorating this solemn day, a soldier correctly and respectfully reminded everyone to maintain decorum.”

Hegseth and his team were at the cemetery for a Veterans Day ceremony that was also attended by Donald Trump and vice-president JD Vance, who both laid wreaths at the memorial in honor of fallen soldiers and delivered remarks afterwards.

The Tomb of the Unknown Soldier at Arlington national cemetery is one of the most sacred war memorials in the country, marking the final resting place of an unknown soldier who was killed in the first world war. An army sentinel from the 3rd US Infantry Regiment – also known as the Old Guard – has been guarding the tomb around the clock, rain or shine, since 1948.

In an article on the US army’s website, Staff Sgt Chadwick Winget, the relief commander, said visitors rarely disrupt the calm intentionally, but sentinels are always ready to react when rules are not being followed. On average, sentinels address noisy crowds roughly two or three times per day.

“It’s usually just them being oblivious,” Wingnet said of some visitors. “They’re talking and not realizing how loud they’re being, or laughing or making jokes amongst their group. It detracts from the other people that are trying to pay their respects.”

Former GOP congressman Adam Kinzinger called the incident “truly abhorrent” and condemned Hegseth as “completely unqualified for the job”.

“Pete Hegseth doesn’t know how to conduct himself, even at The Tomb of the Unknown Soldier at Arlington National Cemetery,” Kinzinger wrote on X. “His behavior is unbecoming of any visitor to the Tomb, let alone that which comes from a Secretary of Defense.”

In a video clip attached to the post, Kinzinger added of Hegseth: “Everything is a show to him. Everything to him is about attention … He is completely unqualified for the job.”

In further comments to CNN, Kinzinger said he could not fathom taking a picture at the memorial, let alone talking and laughing. Kinzinger also commended the sentinel guard for doing his job. “It’s very embarrassing for [Hegseth], and at the same time I’m very proud of the fact that our country held those rules, even in the face of the secretary of defense,” he said.

The sacrifices associated with guarding the memorial and the solemness of the site are “an amazing testament to how much we honour people who have made the sacrifice for this country … and one of the very few places we hold sacred,” he added.

The incident comes just a day after Hegseth narrowly avoided impeachment. House Republicans were able to block the effort to impeach the defense secretary, rejecting allegations that he had repeatedly violated the constitution through his handling of the Iran war and other conflicts globally.

The 211-204 vote came a week after Republicans dramatically lost control of the Senate and House of Representatives in their worst midterm election in more than a half century, and underscored how lawmakers remain wary of crossing Trump, who has signaled his continued support for Hegseth.

Thomas Massie, a Republican congressman who lost his primary after breaking with the president, had in September proposed impeaching Hegseth, alleging an array of illegal acts, including killing civilians in Iran, launching unauthorized operations in Venezuela and Yemen, and retaliating against a Democratic senator.

Democratic minority leader Hakeem Jeffries, who is expected to become the House speaker in the next Congress, has backed the push to impeach Hegseth, accusing the embattled secretary of having “undermined America’s national security”.