Toomey told reporters afterward that Trump didn’t offer any commitments on what proposals he could support and that the timeline on moving forward could slip into next week.

Manchin, along with Chris Murphy (D-Conn.) and Pat Toomey (R-Pa.), the other two senators on the call, have played key roles in crafting gun control legislation in Congress in recent years.

The discussion with the president focused on expanding background checks on gun purchases conducted via commercial sales ― including Internet sales and gun shows ― but not private sales. The House earlier this year passed a universal background check bill toughening federal scrutiny on all gun purchases, but it has faced stiff opposition in the GOP-controlled Senate.

Trump has expressed interest in gun control proposals in the past, often immediately following a horrific mass shooting, only to reverse himself days later.

However, Trump didn’t indicate on the call any preference for legislative proposals toward curbing gun violence and said the lawmakers “should be able to hear back from his staff tomorrow” on the path forward, according to Joe Manchin (D-W.Va.), one of the senators who participated in the call.

WASHINGTON ― A bipartisan trio of senators urged President Donald Trump on Wednesday to expand background checks on gun purchases in a roughly 40-minute conference call they described as productive and “very encouraging.”

Kevin Lamarque / Reuters Sen. Joe Manchin (D-W.Va.), left, and Sen. Pat Toomey (R-Pa.) confer as President Donald Trump discusses school and community safety after the Feb. 14, 2018, massacre in Parkland, Florida. The senators are among a bipartisan group talking again with the president about possible gun control legislation.

Murphy said the group got “into the details for the first time with the president about some of the ways that we could find a bill that will attract support on both sides.” The Connecticut Democrat, who has been a vocal proponent of gun control since the 2012 Newtown elementary school shooting in his state, said he was holding out hope about the prospect of a compromise but that time was quickly running out.

Trump has oscillated widely over the last month about potential legislative solutions on the topic of gun violence in the wake of mass shootings in Texas and Ohio. He remained mercurial about the state of negotiations with lawmakers in remarks at the White House on Wednesday afternoon.

“There are a lot of things under discussion. Some things will never happen and some things can really very much,” Trump said.

Republicans have made it clear they will proceed with a debate on gun legislation only if it has the backing of Trump, who would need to sign it to make it the law. Many of their members, however, remain skeptical about proposals expanding background checks — arguing they won’t do much to prevent mass shootings.

The gunman who killed seven people and injured more than 20 in an Aug. 31 shooting rampage in and around Odessa, Texas, however, purchased his weapon from a private seller, a transaction that does not require a background check.

“It’s a bit of a mixed bag, but we’ll see what the president puts forward,” Senate Majority Whip John Thune (R-S.D.) told HuffPost on Wednesday when asked what the appetite in his conference is for any measure expanding background checks.

Other Republicans were more skeptical about the gun control proposals being discussed in the Senate.

“There’s far too much pulling stuff out of your orifices on this issue,” Sen. John Kennedy (R-La.), an ardent Second Amendment supporter, told HuffPost.

Trump is expected to receive a final briefing about potential legislative proposals from his aides on Thursday. Other items White House officials have explored include “red flag laws,” which are designed to keep guns out of the hands of potentially dangerous people, and mental health reforms. It’s anyone’s guess where he lands, however, and even those closely involved in the talks aren’t certain.

“I’m begging the president to come to the table and agree to a common-sense background checks expansion bill that will save lives. I’m begging my colleagues here to do the same,” Murphy said in a speech on the Senate floor.