WASHINGTON – President Donald Trump on Thursday pressed lawmakers on Capitol Hill to pass “meaningful legislation” to prevent mass shootings after a week in which he has sent mixed signals on his support for tougher regulations on gun sales.

“Just concluded a very good meeting on preventing Mass Shootings. Talks are ongoing w/ both Republicans & Democrats,” the president tweeted Thursday night. “I am hopeful Congress will engage with my Team to pass meaningful legislation that will make a real difference and, most importantly, Save Lives!,” he added.

Trump’s tweets offered no specifics about what kind of legislation he hopes Congress pursues when lawmakers return from their summer recess next month. The tweets follow a dizzying series of statements in which the president has professed his support for tougher background checks and then appeared to back off that position.

White House aides did not immediately respond to questions about who the president met with. There were no such meetings included on Trump's public schedule for Thursday.

The president said Wednesday that while he and other Washington leaders are working on gun control, voters have to remember that "the gun doesn't pull the trigger." At certain times since the mass shootings in El Paso, Texas, and Dayton, Ohio, he has fallen back on talking points from the National Rifle Association about the danger he believes gun regulations pose to the Second Amendment.

More:Pete Buttigieg: NRA has Donald Trump 'by the… base' on background checks

But the president has also signaled an “appetite” for stronger background checks, closing what he has described as “loopholes” in the current system. Gun control advocates have said the biggest loophole in the current system are firearms sales completed at gun shows, but Trump has not indicated which provisions he thinks could be tightened.

“I have an appetite for background checks,” Trump said on Wednesday. “We’re going to be doing background checks. ... We’re going to be filling in some of the loopholes.”

Contributing: Michael Collins