Actor R Lee Ermey, known for his role as foul-mouthed Gunnery Sergeant Hartman in Vietnam War film Full Metal Jacket, has died aged 74.
The former US Marine turned award-winning actor played a host of military men during his career.
Ermey's manager, posting to the actor's Twitter account, said he died from "complications of pneumonia".
"He will be greatly missed by all of us," the message read. "Semper Fi, Gunny. Godspeed."
Born in 1944 in Kansas, Ermey was a staff sergeant in the marine corps in the 1960s and early 1970s, serving tours in Japan and Vietnam. He also served as a real-life drill instructor.
Ermey later drew on his military experience for his breakout role in Stanley Kubrick's 1987 film Full Metal Jacket, winning a Golden Globe nomination for his portrayal of a hardened drill instructor putting young marine corps recruits through basic training.
One popular story about Ermey is that he was initially hired as a technical advisor, but Kubrick was so impressed with his demonstration of a drill instructor's role that he was offered the part.
Ermey's Full Metal Jacket co-stars Matthew Modine and Vincent D'Onofrio were among those to pay tribute to the actor.
Modine used the motto of the US Marine Corps 'Semper Fidelis' - meaning always faithful or always loyal - in his Twitter tribute.
He also quoted lines from Dylan Thomas' poem Do Not Go Gentle Into That Good Night.
In a second tweet, he thanked the marines for helping the actor become "the outstanding person he was. Hard working. Disciplined. Focused. Never complaining."
"There's no doubt his Marine Corp training benefited him with his second career as an actor," wrote Modine, who played Private James T. 'Joker' Davis in the film.
D'Onofrio, who played Private Pyle, called Ermey "the real deal".
Donald Trump Jr posted a long tribute to the actor, saying he was "proud to have had R Lee Ermey as a friend", calling him "a legend and a great American".
In a 2010 interview with the Civilian Marksmanship Programme magazine, Ermey recalled being a "troublemaker and a bit of a hell-raiser" in his youth - eventually ending up in court.
"Basically a silver-haired judge... gave me a choice. He said I could either go into the military - any branch I wanted to go to - or he was going to send me where the sun never shines," he told the magazine.
"And I love sunshine, I don't know about you."
Ermey played many military and police roles on film and television. He featured in Francis Ford Coppola's Apocalypse Now and lent his distinctive voice to animated characters, such as the plastic toy soldier in Pixar's Toy Story films.
He was a board member of powerful US gun lobby group the National Rifle Association (NRA).
In a post on Facebook - since made inaccessible - his manager Bill Rogin said: "It is extremely difficult to truly quantify all of the great things this man has selflessly done for, and on behalf of, our many men and women in uniform.
"Gunnery Sergeant Hartman of Full Metal Jacket fame was a hard and principled man," he wrote. "The real R Lee Ermey was a family man, and a kind and gentle soul."