A day after a listening session to address concerns from survivors of the Parkland school shooting, President Donald Trump pointed to video games and movies as possible causes for violence, as the White House is faced with raising rallies for gun control laws.

“I’m hearing more and more people say the level of violence on video games is really shaping young people’s thoughts,” he said at a meeting on school safety. “And then you go the further step, and that’s the movies.”

“You see these movies, they’re so violent and yet, a kid is able to see the movie if sex isn’t involved,” he went on. “Killing is involved, and maybe they have to put a rating system for that.”

His comments are similar to criticisms that the NRA made in the wake of the Sandy Hook school shootings, in that a problem is the violent culture perpetrated by the entertainment industry.

In 2013, Vice President Joseph Biden met with industry lobbying representatives to talk about on-screen violence, but nothing came of the recommendation to launch an extensive scientific study of the effects on media violence on children.

Movie ratings are administered by the MPAA, but they have come under scrutiny through the years in how they treat depictions of violence versus sex. The video game industry also has a ratings system that is administered through the Entertainment Software Rating Board.

On Wednesday, survivors of the Marjory Stoneman Douglas High School in Parkland, Fla., which killed 17 people, gathered at the White House to talk to Trump in search of solutions. While Trump discussed mental health issues and the idea of teachers being supplied with guns, many of the survivors raised questions about the accessibility of guns in the U.S., especially assault rifles like the shooter’s AR-15.

“I don’t understand why I can still go in a store and buy a weapon of war, an A-R” said Samuel Zeif, a student of Marjory Douglas High School, tearfully. “How is it that easy to buy this type of weapon? How do we not stop this after Columbine, after Sandy Hook? I’m sitting with a mother who lost her son. It’s still happening.”

In a series of tweets early Thursday, Trump suggested allowing “highly trained teachers” to have a gun in the classroom, and added that he will be “strongly pushing Comprehensive Background Checks with an emphasis on Mental Health.”

He continued to broach the idea on Thursday afternoon.

“We have to harden our schools, not soften them. A gun-free zone to a killer or somebody who wants to be a killer, that’s like going in for the ice cream,” he said. “That’s like ‘here I am, take me.’ We have to get smart on gun-free zones. When they see ‘this is a gun-free zone,’ that means that nobody has a gun except them, nobody’s going to be shooting bullets in the other direction. And they see that, it’s such a beautiful target.”

Trump also denied that he suggested arming teachers, although he is open to personnel on school campuses having firearms.

“One of the fake news networks, CNN, said I want teachers to have guns,” he said. “I don’t want teachers to have guns, I want certain highly adept people people that understand weaponry, guns, if they really have that aptitude, because not everybody has an aptitude for a gun, I think a concealed permit for teachers and letting people know there are people in the building with a gun, you won’t have, in my opinion you won’t have these shootings.”