US Defence Secretary Pete Hegseth and members of his team were admonished by an Army guard at the Arlington National Cemetery after he and his entourage appeared to violate the solemn war memorial's rules for decorum.
A video of the Veterans Day observance event shows Hegseth, his wife and senior advisers laughing and talking while posing for photos in front of the Tomb of the Unknown Soldier.
The Army sentinel on duty then steps towards Hegseth and his group and yells: "All visitors will maintain an atmosphere of silence and respect at all times."
Rules on etiquette at the cemetery dictate that visitors speak quietly and do not engage in disrespectful or disorderly conduct.
The tomb, which is one of the country's most sacred war memorials, marks the final resting place of an unknown soldier who was killed in World War I.
A service member from the 3rd Infantry Regiment stands watch over the Tomb 24 hours a day and has done so since 1948.
"While commemorating this solemn day, a soldier correctly and respectfully reminded everyone to maintain decorum," 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."