US President Donald Trump says "serious discussions" are taking place between congressional leaders on "meaningful" background checks for gun owners following two mass shootings.
On Twitter, Mr Trump also said he had spoken to the gun lobby group National Rifle Association (NRA) so their views can be "represented and respected".
The NRA opposes extensive checks.
Democrats want the Senate to be recalled from recess to enact immediate legislation on gun control.
Mr Trump - who did not specify which steps he would support - weighed in after days of disagreement on how the US should respond to its latest mass shootings.
As he prepared to leave the White House on a trip to New York, he said: "Frankly, we need intelligent background checks. This isn't a question of NRA, Republican, or Democrat."
But he singled out mental health issues, saying: "We don't want people who are mentally ill, people who are sick - we don't want them having guns."
Mr Trump earlier tweeted that he was "the biggest second amendment person there is" - referring to the part of the US constitution which grants the right to bear arms - but that "common sense things can be done that are good for everyone!"
Serious discussions are taking place between House and Senate leadership on meaningful Background Checks. I have also been speaking to the NRA, and others, so that their very strong views can be fully represented and respected. Guns should not be placed in the hands of.....— Donald J. Trump (@realDonaldTrump) August 9, 2019
There have been more than 250 mass shootings in the US this year. Last weekend, mass shootings in Dayton, Ohio, and El Paso, Texas, left more than 30 people dead.
Late on Thursday, US Senate Majority Leader Mitch McConnell rejected recalling senators from their August recess. He said the issue would instead be "front and centre" when the Senate reconvenes in September.
Mr McConnell said that calling the Senate back immediately would only result in "political point scoring" and he instead wanted to start discussions during the August break to come back with a coherent plan in September.
Will things change?
For US gun rights advocates, time is an ally. After every new mass-shooting, politicians on the left call for action. Polls show continued public support new gun regulations, including comprehensive background checks on firearm purchases.
The media focus on the victims and note how the US is one of the few nations with such an epidemic of violence. And then, at least when it comes to federal legislation - nothing. Time passes, attention shifts elsewhere, and inertia takes over.
In rebuffing calls to bring the Senate back from its August recess to consider new gun regulations, Mr McConnell - an ardent gun rights supporter - may be counting on this familiar pattern to play out again. With both parties digging in, modest action, perhaps on a red-flag law, may be the only action there is.
The one wild card is Donald Trump. He has expressed support for background checks in the past, and he is doing so again. If legislation is going to pass, however, it will take more than flitting presidential interest. It will take real political muscle and a willingness to take on allies - including the NRA. After embracing gun rights in 2016, is the president up for such a fight?
Mr McConnell seemed to have shifted his tone after speaking with the president, saying that failing to take action would be "unacceptable".
"We've seen entirely too many of these outrageous acts by these mentally deranged people," he said.
Many gun control advocates believe that the ease with which high-powered firearms can be bought is more important than mental health issues.
Some Democrats expressed doubt that the rhetoric would result in meaningful change.
Representative Elijah Cummings said: "We really need to be careful when listening to politicians talk about what they're going to do," to some light laughter at a National Press Club event.
But striking a serious tone, he added: "You have a lot of talk… but in the end, nothing happens."