On Thursday morning, Mr Trump criticised reporting of his remarks, stressing that he spoke of the need to train teachers properly.
"I'm saying that the problems we are facing here today can not be solved by gun laws alone", Rubio said, adding he supported legislation to raise the minimum age to purchase a gun, ban bump stocks and change the background check system.
"If they have the aptitude, I think a concealed permit for having teachers and letting people know that there are people in the building with guns, you won't have - in my opinion - you won't have these shootings", he said. They love this country.
Mark Barden - whose son Daniel was killed in the 2012 shooting at Sandy Hook Elementary School in CT - said more guns was not the answer.
Trump explained that a lot of airline pilots carry guns, and things have taken a turn for the better.More news: United Nations calls for 30-day ceasefire in Eastern Ghouta
The only small glimmer of hope from this bad episode is that young people across America have started to mobilise and have become motivated to seek real gun control law changes.
In the wake of last week's school shooting, some victims and gun rights activists have called for a ban on semiautomatic rifles, such as the AR-15, which was used in the Florida shooting. "If the coach had a firearm in his locker.if he had a firearm, he wouldn't have had to run". But if he had a firearm, he wouldn't have had to run; he would have shot and that would have been the end of it. It takes five to eight minutes for responders, for the police, to come in. Highly trained, gun adept, teachers/coaches would solve the problem instantly, before police arrive.
"A gun-free zone, to a maniac, because they are all cowards, a gun-free zone is, 'let's go in and let's attack'".
USA president Donald Trump has defied many of his supporters in gun lobbying group the National Rifle Association (NRA) by saying assault rifles should be kept out of the hands of anyone under 21. "Congress is in a mood to finally do something on this issue - I hope!"
One idea he did not like was more "active shooter" drills, which some schools hold.
"So this insane man who walked in wouldn't even know who it is that has [a concealed weapon], that's good!" "We know that by and large there's mass opposition to this in the education community".More news: When does The Walking Dead season 8 return?
"Anyone who advocates for arming teachers doesn't understand teachers and doesn't understand schools", Weingarten tweeted Thursday.
The NRA has long proposed more guns at schools to protect them from violence. Highly trained teachers, he continued, would also serve as a "deterrent to the cowards that do this. GREAT DETERRENT!" Trump said.
"We're going to do strong background checks". "We should lower the age to buy a handgun to 18, instead of raising the age to buy an AR15".
Asked for a show of hands, some of those present indicated they would be in support of the measure and others said they were against.
At the White House meeting on Wednesday, Trump listened to Samuel Zeif, a student at Marjory Stoneman Douglas High School in Parkland.
"It should all be at 21", he said. Trump also backs training and arming teachers to provide another line of defense against attackers.More news: Here's The Updated Medal Count After Team USA's Gold Medal In Curling