A measure that would allow citizens with concealed-carry permits in one state to carry their guns into states with stricter gun laws looms as a roadblock for legislative action to bolster the criminal background check system for gun purchases.

The Republican-controlled House passed a bill in December mostly on party lines that attached the so-called concealed-carry reciprocity measure to the Senate’s “Fix-NICS” bill aimed at bolstering enforcement of the current federal background check system.

“We do know there are gaps in the background check system that need to be plugged. And we passed a bill to do that,” House Speaker Paul D. Ryan of Wisconsin said Tuesday at a GOP leadership news conference.

The Fix-NICS bill, proposed by Senate Majority Whip John Cornyn of Texas and Sen. Christopher S. Murphy, D-Conn., has bipartisan support, including from Senate Minority Leader Charles E. Schumer of New York. Concealed-carry reciprocity? Not so much.

But House GOP leadership indicated Tuesday morning at their weekly press conference that they were not ready to let the Senate’s background check bill stand alone from the House’s concealed-carry addendum.

“We think the Senate should accept our bill,” Ryan said, when asked about decoupling the measures. Ryan signaled it would be back to the drawing board if the Senate — which is not expected to vote on the House bill — declines.

On Monday, 12 days after a gunman armed with an AR-15 semiautomatic rifle killed 17 people at their school, students from Marjory Stoneman Douglas High School in Parkland, Florida, met with lawmakers on Capitol Hill to discuss what happened and what could be done to prevent a similar shooting in the future.

The students and lawmakers discussed potential policy solutions. And some Republican lawmakers stressed to the students the “breakdowns at various levels of government” that could have prevented the shooting, House Majority Whip Steve Scalise of Louisiana, who met with the students Monday, said.

“The FBI had this guy’s name on a silver platter,” Scalise said of 19-year-old Nikolas Cruz, who has been charged with 17 counts of murder for the rampage.

At least 45 phone calls reporting concerning or violent behavior by Cruz or his brother were made to the Broward County sheriff’s department from 2008 to 2017, CNN reported.

The FBI also received a call on Jan. 5 from a woman who said Cruz was “going to explode” and that he might end up entering “a school and just shooting the place up.”

“Somewhere along the way in the FBI’s chain of command, they let this go,” Scalise said at Tuesday’s press conference, adding that investigators should probe the offices responsible for letting Cruz’s case slip through the cracks.

Scalise, Ryan, and House Majority Leader Kevin McCarthy have each stressed the failures of relevant agencies in Florida to enforce existing measures that could have prevented Cruz from obtaining a gun. That messaging could act as a hedge against the potential backlash if Congress cannot pass any gun reform bills.

Ryan supported President Donald Trump’s idea to arm some schoolteachers with weapons and train them to use them, but said that’s a step best left to local government bodies to greenlight.

“That is a really good question for local government,” Ryan said. “As a parent, as a citizen,” Ryan said he thinks it is a good idea. But “as the speaker,” he believes states and local school boards should decide how to move forward with that proposal.

Members of the House Freedom Caucus — the main proponents of the concealed-carry reciprocity measure — mulled policy ideas during a meeting Monday night to address the country’s ongoing mass shooting epidemic, their chairman, Mark Meadows of North Carolina, said Tuesday.

The Freedom Caucus was working Tuesday to put together a more formal list of policy options, Meadows said. He declined to elaborate on what that list could include.

Meadows is confident Congress will take some sort of action after the latest shooting in Parkland, adding that the White House has been working on “an hourly basis” in recent days to address the epidemic.

“I’m certain that something will happen,” Meadows said. “It’s just a matter of how broad the scope of those initiatives will be.”