President Donald Trump is denying reports he told the NRA chief that expanded background checks for gun buyers are "off the table," and now says he backs such measures.

Trump spoke to reporters outside the White House Wednesday as he appears to waver back and forth on how he plans to address gun violence in the United States.

He said Wednesday he is considering ways to make background checks stronger, but warned of what he calls the "slippery slope" he believes would restrict legal gun ownership.

"I want guns in the hands of people that are mentally stable," Trump said Wednesday. "I want them to be easily able to get a gun. But people who are insane, people who are sick, I don't want them to be able to get a gun."

Trump expressed strong support for more background checks after two gunmen massacred 31 people earlier this month in EL Paso, Texas, and Dayton, Ohio.

But he seemed to grow lukewarm toward tougher gun measures after conversations with Wayne LaPierre, head of the National Rifle Association, White House officials have said.

A report by The Atlantic magazine Tuesday said Trump told LaPierre that expanded background checks were "off the table."

Trump said Wednesday, "We have a lot of background checks right now, but there are certain weaknesses. We want to fix the weaknesses."

He has also noted that many of his supporters are strong believers in the Second Amendment of the U.S. Constitution, which guarantees citizens the right to own guns.

Some Democrats who wholly support more gun control say they are upset with Trump's perceived back-and-forth on background checks.

"It's time for Republicans and President Trump to decide whose side they're on," Connecticut Sen. Chris Murphy said. "Are they going to stand with 90% of Americans who want universal background checks, or are they going to once again kowtow to the desires of the gun lobby?"

Senate Majority Leader Chuck Schumer tweeted that Trump's "retreats are heartbreaking, particularly for the families of the victims of gun violence."

White House and congressional teams from both parties have been talking about ways to strengthen gun laws. But the NRA has been a major force on Capitol Hill in opposing more regulations. 

A gunman killed 22 people at a Walmart store in El Paso Aug. 3 in a shooting that appears to have targeted Mexicans. The suspect is in jail.

Hours later, another gunman shot and killed nine others in Dayton before police killed him. The motive for that attack is still unclear

Both shooters used military-style assault weapons.

The killings, along with past mass shootings and a recent spate of threatened shootings, have renewed the nationwide debate over gun control in the U.S.

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