House Republican leaders on Tuesday ruled out acting swiftly to respond to the shooting that killed 17 at a Florida high school, spurring the surviving students to lead calls for legislative action.

With President Trump and the Senate also moving deliberately on the issue, neither House Speaker Paul D. Ryan (Wis.) nor other top GOP leaders would commit to holding a vote on modest gun-related measures that have broad bipartisan support.

The Fix NICS Act would create incentives and penalties to improve reporting to the National Instant Criminal Background Check System and has the backing of the National Rifle Association. Another bill would ban “bump stock” accessories that allow a semiautomatic rifle to mimic the rapid fire of a machine gun.

The House passed a version of the Fix NICS measure in December, in conjunction with a controversial provision that would force states to recognize concealed-carry licenses from other states. The Senate is exploring passing Fix NICS as a standalone measure as soon as this week, but Ryan would not say Tuesday whether he would bring that or a bump-stock ban up for a vote.

“We’re waiting to see what the Senate can do,” he said, adding, “We obviously think the Senate should take our whole bill, but if the Senate cannot do that, then we’ll discuss and cross that bridge when we get to it.”

Speaking on the Senate floor shortly afterward, Sen. John Cornyn (R-Tex.) — the majority whip and a co-sponsor of the Fix NICS bill — called on his colleagues to pass the legislation.

With gun control advocates facing off against gun rights groups after Parkland, each side is trying to set goalposts for what is - and isn't - on the table. (Jenny Starrs/The Washington Post)

“There’s a lot of other things we can do, but the one thing we can do this week before we go home is to pass the Fix NICS bill and to send it to the House and then to the president and sign it into law,” he said. “It will save lives.”

But there are obstacles. One Republican senator, Mike Lee (Utah), is blocking the bill from rapid consideration because of constitutional objections, while in the House, hard-line conservatives have similar concerns that could make it tricky for Ryan to move the measure through the chamber.

Democrats, meanwhile, are pushing for broader legislation to improve background checks, although they are not openly threatening to block Cornyn’s bill.

“What will prevent future tragedy? Comprehensive background checks will; the Fix NICS bill will not,” said Senate Minority Leader Charles E. Schumer (D-N.Y.). “Let’s not set our sights too narrow or squander this moment.”

House lawmakers are set to finish their business for the week on Tuesday evening, and no hearings or other action responding to the massacre in Parkland, Fla., have been scheduled in either chamber. Although the Senate will remain at work later this week, House leaders cited the scheduled lying-in-honor of the Rev. Billy Graham in the Capitol rotunda on Wednesday and Thursday for cutting their workweek short.

The holding pattern comes as President Trump has floated potential actions, including a higher age limit on rifle purchases, arming teachers and volunteer school guards, and beefing up background checks. But he has not formally endorsed any particular course of action, and that has left his Republican allies in Congress unsure of how to proceed. They have turned to a playbook familiar from past acts of mass violence — where initial demands for action faded with time and the emergence of new headlines.

“My impression is that they’ve not communicated a lot of very clear thoughts behind closed doors,” Sen. Chris Murphy (D-Conn.), one of the most prominent gun control advocates in Congress, said of the Trump administration. “My sense is, the White House is still trying to figure out where the president is.”

Murphy and Cornyn are among a number of lawmakers who plan to attend a White House summit on gun policy Wednesday. Sen. Dianne Feinstein (D-Calif.), who has written a bill that would ban military-style “assault weapons,” also has been invited, an aide familiar with the meeting said.

Cornyn said that he spoke with Trump over the weekend and that the president has “a lot of ideas” but that he hasn’t discussed with him any legislation on background checks that’s broader than the Fix NICS Act. Murphy, meanwhile, said he thinks the White House would be willing to go beyond the bare-bones bill for a more expansive background-checks measure.

Cornyn warned against trying to overreach. “I worry that we’re going to be leaving here by Thursday or Friday and end up empty-handed,” he said. “I think that would be a tragedy.”

Ryan on Tuesday focused on questions about the actions that local and federal law enforcement agencies took before and during the shooting. “There was a colossal breakdown, and we need to get to the bottom of this, how these breakdowns occurred,” he said.

House Majority Whip Steve Scalise (R-La.), who was shot last year by a would-be assassin who targeted Republican lawmakers practicing for a charity baseball game, also focused on the law enforcement failures. Scalise met Monday with a group of surviving students from Marjory Stoneman Douglas High School in Parkland, where the Feb. 14 massacre occurred, in a discussion that, he said, touched on the policy responses to the shooting and the institutional breakdowns that preceded it.

“As people are contemplating new laws, I think the most important thing we can look at is: What about all the laws that are already on the books that were not enforced, that were not properly implemented?” he said, adding of accused Parkland killer Nikolas Cruz, 19, “The FBI has this guy’s name on a silver platter.”

But neither Ryan nor Scalise announced any formal inquiry into the shooting by the relevant House committees, which requested an FBI briefing on the failures in the immediate aftermath of the massacre, but have taken no public action since.

The Douglas High students, approached by a reporter Monday, declined to speak about their advocacy efforts on Capitol Hill. They have attended meetings with lawmakers from both parties, including House Minority Leader Nancy Pelosi (D-Calif.), and a Tuesday morning meeting of the House Democratic Caucus. Schumer said he planned to meet with them Tuesday.

Since the shooting, students have called for new gun restrictions as part of any legislative response, including a new age limit of 21 for buyers of long guns, matching the federal limit for handgun buyers. But Republican lawmakers have sought to turn the discussion toward law enforcement failures, mental health and school security.

“Of course we want to listen to these kids, but we also want to make sure that we protect people’s due process rights and legal, constitutional rights while making sure that people who should not get guns don’t get them,” Ryan said, before turning to “bigger questions of our culture.”

“What are we teaching our kids?” he continued. “Look at the violence in our culture. . . . There’s bigger questions here than a narrow law. What about law enforcement? What about school resource officers? What about the FBI? What about background checks? Those are all things that we have to get lots of answers to.”