A “CLOSED” sign hangs on the door of Sunrise Tactical Supply gun shop in Coral Springs, Fla., on Thursday, Feb. 15, 2018. Two federal law enforcement officials say the Smith & Wesson M&P 15 rifle used in the deadly rampage at Marjory Stoneman Douglas High School in Parkland was purchased legally at the gun shop. (AP Photo/Allen G. Breed)

President Donald Trump signaled support for one piece of gun control legislation on Monday, five days after a mass shooting at a Florida high school left 17 people dead and scores injured.

“The president is supportive of efforts to improve the federal background check system,” Sarah Huckabee Sanders, the White House press secretary, wrote in a statement Monday morning.

Sanders said the president spoke to Sen. John Cornyn, R-Texas, on Friday to express support for the bill Cornyn has introduced with Sen. Chris Murphy, D-Conn. The bill is still being amended, the White House cautioned.

The statement did not address how the president would react to more aggressive gun control measures.

The senators’ bill is narrow in focus, reinforcing the requirement that federal agencies report all criminal infractions to the National Instant Criminal Background Check System (NICS) and creating financial incentives for states to do so, as well.

Federal agencies are required to report various felonies, indictments and other crimes – including domestic assaults – into the federal database, but Congress has no power to compel states to do the same. The Murphy-Cornyn legislation would offer direct financial incentives, as well as favorable future access to other federal assistance programs, to states that report infractions into the system.

The powerful National Rifle Association has not opposed the bill like it has more exhaustive pieces of legislation, such as banning assault rifles or limiting the sale of high-capacity magazines.

It’s unclear whether the legislation will go forward. After a mass shooting in Las Vegas last year, officials said they were studying a ban on bump stocks, an attachment that allows a rifle to fire more frequently.

Over the weekend at his Mar-a-Lago estate in Florida, Trump weighed gun control measures in conversations with friends, according to people who spoke to him. He told them he was affected by seeing victims at a Florida hospital on Friday evening.

Trump has faced two of the country’s deadliest mass shootings as president, including a gunman opening fire from his hotel room in Las Vegas in October and the shooter at the Parkland school last week. Police say 19-year-old Nikolas Cruz admitted last week that he walked into the school – where he had been a former student – and began shooting at students and staff.

Thus far, Trump has not mentioned limiting gun access in his response to the most recent shooting. He initially focused on mental health issues, calling the shooting suspect “mentally disturbed” and saying that he wanted to support local jurisdictions in addressing mental health issues. He said that fixes in the system could prevent future crimes.

Trump also said that people needed to report more to law enforcement. “Neighbors and classmates knew he was a big problem. Must always report such instances to authorities, again and again!” he said Thursday in a tweet.

After the FBI admitted last week that it failed to investigate a warning from a person close to Cruz that he spoke about violence and might be capable of shooting up a school, Trump criticized the agency’s response. He accused the bureau of being too focused on finding wrongdoing related to him and his 2016 presidential campaign to follow up on a tip. His claim that the Russia investigation had anything to do with the Florida office’s failures was widely denounced.

The president has publicly said little about the victims, but he refrained from golfing, which aides said was to show respect. On Monday, Trump arrived at his gold course around 9 a.m.

“Have a great, but very reflective, Presidents’ Day!” he tweeted.

The Post’s Karoun Demirjian contributed to this report.

Dozens of semi-automatic rifles line a pair of walls in a gun shop Tuesday, Nov. 7, 2017, in Lynnwood, Wash. (AP file photo)