Trump spoke to Senator John Cornyn, a Republican, on Friday about a bipartisan bill that he and Democratic Senator Chris Murphy introduced to improve federal compliance with criminal background checks, White House spokeswoman Sarah Sanders said.

"While discussions are ongoing and revisions are being considered, the president is supportive of efforts to improve the federal background check system," Sanders said in a statement.

Students, many using the mantra NeverAgain, are mobilizing around the country in favor of stronger gun laws after the deadliest high school shooting in U.S. history took place on Wednesday at Florida's Marjory Stoneman Douglas High School, where a former student is accused of murdering 17 people using an assault-style rifle.

Previous mass shootings in the United States have also stirred outrage and calls for action to tighten U.S. gun laws, with few results in Congress.

Trump, who visited survivors of the shooting and law enforcement officials on Friday night before spending the weekend at his property in Palm Spring, Florida, is a strong supporter of gun rights and won the endorsement of the National Rifle Association, the powerful gun lobby group, for his 2016 presidential campaign.

He angered some students by suggesting in a tweet on Saturday that the Federal Bureau of Investigation had missed signs that the school shooter was troubled because it was distracted by its investigation into Russian meddling in the 2016 U.S. election. The FBI has acknowledged it failed to act on a tip flagging concerns about the suspect, Nikolas Cruz.

Many Republicans generally oppose measures to tighten gun restrictions, citing the U.S. Constitution's Second Amendment protection of the right to bear arms.

Former President Barack Obama and many of his fellow Democrats unsuccessfully pushed to pass gun control legislation after a gunman killed 20 children and six adults at Sandy Hook Elementary School in Newtown, Connecticut, in 2012.

Cornyn and Murphy introduced their bill to improve federal background checks last November, days after a gunman killed more than two dozen people in a church in Texas.

The bill, called the Fix NICS Act, would ensure that states and federal agencies comply with existing law on reporting criminal history records to the national background check system.

Cornyn, of Texas, had complained when introducing the legislation that compliance by agencies was “lousy.”

Students are planning a "March For Our Lives" in Washington on March 24 to call attention to school safety and ask lawmakers to enact gun control. [nL2N1Q900C]

Some students reacted with caution to Trump's support on background checks.

“We want to prevent mass shootings from happening and while this could have happened with other types of weapons, NeverAgain believes school safety should be priority right now, not just background checks," said Marjory Stoneman Douglas High School student Kali Clougherty, 18, referring to a campaign for gun control. "This is about the victims. Don’t forget that; we never will."

Trump is scheduled to host a "listening session" with high school students and teachers on Wednesday.

Dozens of high school students protested in front of the White House on Monday, chanting “We want safe schools!” and “Hey! Hey! NRA how many kids did you kill today?”

Crystal Jordan, a 15-year old from Spotsylvania, Virginia, said it was scary to go to school now.

“It’s OK to obtain a gun, like a handgun, but not an assault rifle,” she said, adding that she hoped Trump and Congress would issue laws to strengthen background checks, ban assault rifles and prevent people with mental problems from accessing guns.