Students are evacuated from Marjory Stoneman Douglas High School during a shooting incident in Parkland, Florida, Feb. 14, 2018 in a still image from video.
Students are evacuated from Marjory Stoneman Douglas High School during a shooting incident in Parkland, Florida, Feb. 14, 2018 in a still image from video.

Survivors of last week's Florida high school massacre have announced a march on Washington and other major U.S. cities next month to demand tangible action so to prevent future school shootings.

"We are going to be marching together as students, begging for our lives," student Cameron Kasky told ABC television's This Week broadcast Sunday. "This has happened before and change hasn't come. This is it."

Kasky said one of the reasons for the march is to pin "a badge of shame" on any politician who is accepting money from the National Rifle Association. She said the NRA is promoting a gun culture that leads to such horrors.

Another student, Emma Gonzalez, told ABC that President Donald Trump, Florida Senator Marco Rubio, and Governor Rick Scott all have NRA support. She said students "want to give them the opportunity to be on the right side of this."

The White House says President Trump will host what it calls a "listening session" with high school students and teachers Wednesday, but did not give details.

Trump criticized the FBI for "missing signals" about the intentions of the accused shooter Nikolas Cruz more than a month before he allegedly killed 17 people at  Marjory Stoneman Douglas High School, in Parkland, Florida.

"Very sad that the FBI missed all of the many signals sent out by the Florida school shooter. This is not acceptable," Trump tweeted Saturday night. "They are spending too much time trying to prove Russian collusion with the Trump campaign — there is no collusion. Get back to the basics and make us all proud!"

A family sits around one of 17 crosses at a memori
A family sits around one of 17 crosses at a memorial for the victims of the shooting at Marjory Stoneman Douglas High School in Parkland, Florida, Feb. 16, 2018.

The FBI admitted it did not act on a tipoff in January about Cruz. The FBI said someone with a close relationship to Cruz had called in information on January 5 about the teenager's "gun ownership, desire to kill people, erratic behavior and disturbing social media posts, as well as the potential of him conducting a school shooting." 

U.S. Attorney General Jeff Sessions ordered an immediate review of how the Justice Department and the FBI respond to warnings about potential mass killers.

A video monitor shows school shooting suspect Niko
A video monitor shows school shooting suspect Nikolas Cruz (C) making an appearance before Judge Kim Theresa Mollica in Broward County Court, Thursday, Feb. 15, 2018, in Fort Lauderdale, Fla.

Meanwhile, Florida Republican Senator Marco Rubio threw his support Sunday behind a Democratic-sponsored state bill that would let courts allow police to seize guns from those who are determined to be a danger to others.

Rubio told a Florida television station the law may have prevented the school massacre.

California already has such a law. But gun rights advocates oppose it, saying it would take away guns from those who are innocent of any crimes.

FILE - Assault weapons and hand guns are seen for
FILE - Assault weapons and hand guns are seen for sale at Capitol City Arms Supply in Springfield, Ill.

Several U.S. lawmakers are calling for stiffer background checks of gun buyers, but Congress has shown no inclination to stop the sale of assault weapons, even as national polls in the U.S. show widespread support among voters for such a ban.

Republican Senator James Lankford of Oklahoma told NBC's Meet the Press, "I have no issue with more background checks. All the warning signs were there" about Cruz's mental state and intentions.

"The tragedy we saw in Parkland is unthinkable," Senator Bernie Sanders, an independent from Vermont, told the same show. He said the loophole that allows 40 percent of guns sold in the U.S. to occur without background checks needs to be closed.

But Cruz bought the semi-automatic AR-15 rifle legally after such a background check.

President Donald Trump, center, accompanied by fir
President Donald Trump, center, accompanied by first lady Melania Trump, right, and Dr. Igor Nichiporenko, left, speak to reporters while visiting with medical staff and victims of a mass shooting at a local school in Pompano Beach, Fla., Feb. 16, 2018.

President Trump has yet to directly say the words "guns" or "gun control" in his remarks on the tragedy. He has called it a matter of mental health and more school security.

Those who oppose stricter gun control agree with the president. They say there is no way someone with a troubled past like Cruz, who talked about plans to buy a gun, was thrown out of school for causing trouble, and even talked about becoming a school shooter should have been allowed to get his hands on such a weapon.

Marjory Stoneman Douglas High School student Emma
Marjory Stoneman Douglas High School student Emma Gonzalez reacts during her speech at a rally for gun control at the U.S. Courthouse in Fort Lauderdale, Fla., Feb. 17, 2018.

The problem, they say, is lax enforcement of the current gun control laws already on the books and that the majority of gun owners are responsible citizens who like to hunt, shoot for sport, or want to protect their homes. Their number one rule is safety first.

Gun control advocates say the AR-15 Cruz used has only one purpose – to kill as many people as possible – and that such weapons must be banned for commercial sale and private use. They say the constitutional right to bear arms was never meant to include such weapons of mass murder.

WATCH: Gun law

?Cruz is being held at the Broward County Florida jail without bond and faces 17 counts of premeditated murder. Authorities say he has admitted carrying out the shooting rampage.

Meanwhile, about 60 kilometers away at the Dade County fairgrounds, hundreds of gun enthusiasts attended a gun show Sunday featuring more than 100 vendors of firearms and accessories.

Show manager Jorge Fernandez told Reuters the company holding the event, Florida Gun Shows, decided against canceling the show because of financial concerns.