British tennis player Andy Murray said the deaths of 19 children and two teachers in a shooting at a school in Texas last week made him "angry" and "incredibly upset".
Murray was a pupil at Dunblane Primary School in Scotland in March 1996, when 16 children and a teacher were murdered by gunman Thomas Hamilton.
"I think there's been over 200 mass shootings in America this year and nothing changes," he told BBC Sport.
"I can't understand that."
The shooting in Uvalde on 24 May has provoked new calls for gun control measures in the United States, although several senior Republicans have already expressed their opposition to tighter rules on gun ownership, such as background checks.
On Friday, former US president Donald Trump told the National Rifle Association's annual conference that decent Americans should be allowed firearms to defend themselves against "evil".
And Texas senator Ted Cruz has accused Democrats and the media of seeking to "politicise" the shooting to "restrict the constitutional rights of law-abiding citizens".
The US Department of Justice says it will investigate the police response to the mass shooting.
But Murray believes that changes need to happen.
"My feeling is that surely at some stage you do something different," he added.
"You can't keep approaching the problem by buying more guns and having more guns in the country. I don't see how that that that solves it.
"But I could be wrong. Let's maybe try something different and see if you get a different outcome.
"I heard something on the radio the other day and it was a child from that school, you know, and I experienced a similar thing when I was at Dunblane and a teacher like, coming out and waving all of the children, like under tables and telling them to go and hide.
"And it was a kid telling exactly the same story about how she survived it.
"They were saying that they go through these drills, as young children, as seven-, eight-year-old children. How? How is that normal that children should be having to go through drills, like in case someone comes into a school with a gun?
"I don't get it - just, yeah, it's really, really upsetting and I hope they make some changes."