U.S. President Donald Trump(2rd, L) speaks during a listening session on school safety at the White House in Washington D.C., the United States on Feb 21, 2018. U.S. President Donald Trump promised strong background checks and mental health screenings for gun buyers as he heard pleas from survivors of the recent Florida school shooting and families affected at the White House on Wednesday. (Xinhua/Ting Shen)

WASHINGTON, Feb. 21 (Xinhua) -- U.S. President Donald Trump promised strong background checks and mental health screenings for gun buyers as he heard pleas from survivors of the recent Florida school shooting and families affected at the White House on Wednesday.

"We're going to be very strong on background checks ... very strong emphasis on the mental health," Trump told students and family members affected by last week's high school massacre in Florida and other mass shootings in the past.

The president suggested that some educators could be trained in the use of firearms to deter potential shooters.

"It's called concealed carry," Trump said. "Where a teacher would have a concealed gun on them, they would go for special training and they would be there and you would no longer have a gun-free zone."

"A gun-free zone is, let's go in and let's attack," he said.

"You can't have 100 security guards in Stoneman Douglas," he said, referring to the Marjory Stoneman Douglas High School in Florida where 19-year-old Nikolas Cruz killed 14 students and three teachers with an AR-15- style assault rifle last week.

"It would be teachers and coaches," Trump said, suggesting that arming 20 percent of the teaching force could be a solution. He also said that if the school's assistant football coach Aaron Feis, who shielded students from being shot but died of gunshots himself, had a firearm in his locker, he could have shot Cruz.

However, Trump conceded that concealed carry "only works" with people who are "very adept at using firearms."

Trump heard emotional pleas from those affected by school shootings as they urged the president to take action to make schools more secure and support additional gun control measures.

"I am a survivor," Julia Cordover, a senior class president at the Parkland school, told Trump. "I was lucky enough to come home from school unlike some of my other class and it's very scary knowing that a lot of people did not have this opportunity to be here," she said.

She pressed the president to ensure that "no person in this world will ever have to go through" such a tragedy again.

Andrew Pollack, whose 18-year-old daughter Meadow was among the 17 victims of the Florida shooting, said it was far too easy for people like Cruz to get their hands on guns.

"I can't get on a plane with a bottle of water," Pollack said. "But some animal can walk into a school and kill our children."

"We as a country failed our children," the anguished father stressed as he proposed a fix for schools first.

Samuel Zeif, who lost his best friend when Cruz opened fire at the Florida high school, said he was there to use his voice because his friend couldn't.

Zeif, 18, said he fully respected the Second Amendment that protects gun ownership in the country but questioned why Cruz was permitted to buy an assault rifle, which he called a "weapon of war".