President Donald Trump said Wednesday the administration is going to strengthen background checks for gun purchases and “put a strong emphasis on mental health,” as he promised students and families “we are going to get it done.”

The president, Vice President Mike Pence and Education Secretary Betsy DeVos hosted students, teachers and families affected by the Parkland, Fla., high school shooting for a "listening session" at the White House on Wednesday, which lasted close to two hours.

Exactly one week ago, 19-year-old Nikolas Cruz, whom the president described as "a sick guy," opened fire at the high school and now is charged with killing 17 teachers and students with an AR-15 rifle.

“We are going to be very strong on background checks, and put a very strong emphasis on the mental health of somebody,” Trump said at the beginning of the listening session. “We’re going to talk and get it done. It’s been going on too long, too many instances and we’re going to get it done.”

Students and parents from Marjory Stoneman Douglas High School in Parkland, along with Parkland city Mayor Christine Hunschofsky, attended the White House session, along with members of Sandy Hook Promise, a national non-profit organization based in Newtown, Conn., and led by several family members whose loved ones were killed in the tragic Dec. 14, 2012, mass shooting at Sandy Hook Elementary School. Students from Friendship Public Charter School, Parkmont, and Thurgood Marshall Academy in Washington, D.C., also attended.

Parkland Student Body President Julia Cordover opened the session with emotional remarks for the group.

“I’m a survivor. I want you all to emphasize the point that I survived,” Cordover said. “I was lucky enough to come home from school and it is very scary to know that a lot of people did not have the opportunity to be here.”

Cordover thanked the president for addressing bump stocks earlier in the week.

The president directed Attorney General Jeff Sessions to create new regulations to ban firearm modifiers, including the “bump stock” used in the Las Vegas massacre in October 2017.

A memo released by the White House earlier this week directed the DOJ to propose a rule “banning all devices that turn legal weapons into machineguns.”

The president asked for suggestions to prevent school shootings, leaving the floor open to parents and teachers.

A parent from Parkland High School suggested that a select few teachers, administrators, or other school employees volunteer to become a designated “undercover police officer,” to manage a potential tragedy prior to the arrival of first responders.

“If a tragedy strikes, can we wait for first responders to get to the campus minutes later?” the parent said. “The challenge becomes, once it starts, to end it as quickly as possible.”

The president said the administration would look “very strongly” at the option for “concealed carry” at schools, but acknowledged that “a lot of people will be opposed to it.”

“Concealed carry only works for people that are very adept at carrying a gun,” Trump said. “Where a teacher would have a concealed gun on them, go for special training and they would be there and you would no longer have a gun free zone.”

Trump added: “A gun-free zone to a maniac, they’re all cowards, it’s ‘let’s go in and attack because bullets aren’t coming at us.’”

The president said that an attack lasts, on average “three minutes.”

“It takes five to eight minutes for first responders. So the attack is over. If you had a teacher who was adept at firearms, they could very well end [the attack],” Trump said. “We are looking at that very strongly. A lot of people will be opposed to it. A lot of people are gonna like it.”

Trump suggested having “20 percent of your teaching force” representing the “type of talent” capable of concealed carry. Trump also floated the idea to add security, like former “marines, people who left the Air Force” to be “spread evenly throughout the school.”

The president has also signaled a willingness to raise the minimum age for purchasing certain firearms in the wake of last week’s school shooting in Parkland.

A White House source told Fox News on Wednesday that Trump is open to a number of measures to address mass shootings, including a rise in the minimum age for buying firearms.

Under current federal law, licensed firearm dealers cannot sell handguns to people under 21 and cannot sell long guns to people under 18, according to the Giffords Law Center, which tracks gun laws and advocates for more restrictions. Some states already impose laws with tighter minimum age requirements.

The National Rifle Association quickly rejected any talk of raising the age for buying long guns to 21.

"Legislative proposals that prevent law-abiding adults aged 18-20 years old from acquiring rifles and shotguns effectively prohibits them for purchasing any firearm, thus depriving them of their constitutional right to self-protection," the group said in a statement.

It is unclear, however, whether Trump will push for a change in federal law, or encourage a change at the state level.

The president has expressed support for the Second Amendment and said he’s against reflexive gun control measures that wouldn’t stop tragedies. The NRA endorsed Trump in the 2016 presidential election, and has yet to comment on the president’s current stance on gun control.

“Whether we are Republican or Democrat, we must now focus on strengthening Background Checks!” Trump tweeted Tuesday.

The listening session, Trump’s openness to tightening age restrictions, and the directive to the Justice Department reflect a different response from the White House than in the aftermath of previous tragedies.

Following the Las Vegas massacre, White House press secretary Sarah Sanders said that it was “premature to discuss policy when we don’t know all the facts,” and added, “we can have those policy conversations, but today is not the day.”

Republican Florida Gov. Rick Scott also is slated to meet with students from Parkland Wednesday evening.

"In addition to what we’re going to with background checks, we’re going to go very strong into age of purchase, and very strongly into the mental health aspect of what’s going on," Trump said. "This person, who was very sick, and people knew he was very sick. We’re also going to look at the institutions, what you do when you find someone like this."

He added: "All I can say is we’re fighting hard for you and we will not stop. I grieve for you. There can be nothing worse than what you’ve gone through. Thank you for pouring out your hearts because the world is watching and we’re going to come up with a solution."

Fox News’ John Roberts and Alex Pappas contributed to this report. The Associated Press also contributed to this report.