Prince Harry shot at Taliban insurgents during his time as an Army helicopter pilot in Afghanistan, he says.
The prince, whose four-month deployment to the country has just ended, spoke about his role as an Apache co-pilot gunner, and whether he had killed.
"Yeah, so lots of people have. The squadron's been out here. Everyone's fired a certain amount," he said.
"If there's people trying to do bad stuff to our guys, then we'll take them out of the game."
Prince Harry left Afghanistan on Monday. News teams were allowed to interview him during his deployment, if they agreed to delay broadcast until he had left the country.
As well as discussing his role in Afghanistan, he talked about various other issues, including that he had "let my family down" when he was pictured naked in a Las Vegas hotel room last year.
He said this was "probably a classic example of me probably being too much Army and not enough prince."
But he added: "But at the end of the day I was in a private area and there should have been a certain amount of privacy that one should expect."
He also talked about:
- how being in Afghanistan is "as normal as it's going to get" for him, and even though "everyone has a good old gawp" in the canteen, "I'm one of the guys, I don't get treated any differently."
- how for him and his brother, Prince William, "our service towards our country in the military... will always come first"
- how he "can't wait to be an uncle", but hoped the Duchess of Cambridge would be allowed privacy during her pregnancy, adding: "I think it's very unfair that they were forced to publicise it when they were, but that's just the media for you."
On his role in Afghanistan, one journalist said: "You are the man with the trigger in your hand, and if called upon, you will fire, and presumably you have and you will kill the enemy?"
The prince responded: "Yeah, so lots of people have. The squadron's been out here. Everyone's fired a certain amount. Probably a little bit more than this time last year, to a certain extent, but that's just the way that its balanced out. Mainly due to weather, well whatever the reasons, I don't know.
"We fire when we have to, take a life to save a life, but essentially we're more of a deterrent than anything else."
He said missions to recover injured troops were a key role.
"Our job out here is to make sure the guys are safe on the ground.
"Now if that means shooting at someone who's shooting at them, then we'll do it."
'Stuck in Bastion'
Prince Harry is the first member of the Royal Family to see active combat since his uncle, the Duke of York, fought in the Falklands War.
Captain Wales, as the prince is known in the military, arrived for his second tour as part of the 100-strong 662 Squadron, 3 Regiment, Army Air Corps in September.
Within days of arriving, Camp Bastion was attacked by Taliban insurgents. Prince Harry was moved under guard to a secure location during the attack.
Prince Harry said: "Obviously the papers back home were like 'this is all against me'. No-one really knows yet. But either way, this camp is in the middle of Afghanistan and it should be expected to be attacked at any point... and it was on my birthday, so it was a bit of a reality check."
His first tour was cut short in 2008 after 10 weeks because a media blackout was broken. He was removed from Afghanistan in case he became a target.
Then he was part of ground forces, calling in air strikes against enemy positions. He was disappointed to be withdrawn, and determined to return to front-line combat.
He said: "My choice would have been back out on the ground with my regiment - that sounds quite spoilt when I'm standing in front of this [helicopter], £45 million worth, but hopefully my friends and family back home know exactly what I'm talking about."
He expressed support for his older brother, William, to serve in combat.
William currently flies search and rescue missions from RAF Valley on Anglesey.
"Obviously he'd love to be out here and I don't see why to be honest with you, I don't see why he couldn't.... no-one knows he's in the cockpit."
He added: "Yes, he'd get shot at but, you know, if the guys who are doing the same job as us are being shot at on the ground, I don't think there's anything wrong with us being shot at as well.
"People back home have issues with that, but we're not special - the guys out there are. Simple as that."
He also described how he juggled his different roles in life.
"You've got to be able to flick the switch all the time.
"I think I said a while back there's three 'me's, as it were. One in the army, one socially - my own private time - and one sort of with the family and stuff like that.
"So, you know, there is a switch and I flick it when necessary. And I like to think it's measured and balanced... Army comes first - it is my work at the end of the day."