Jeffrey Swanson, a professor in psychiatry at Duke University School of Medicine, earlier told AFP the overwhelming majority of the 10 million Americans with serious mental illnesses do not engage in violent behavior, and most mass shooters do not have "serious identifiable mental illnesses" such as schizophrenia.
"These people are mentally ill".
Trump is under pressure to curb gun violence following two mass shootings that killed dozens of people this month in Texas and Ohio.
"It's them. They pull the trigger".
Trump said he was giving "major consideration to building new facilities for those in need" and "taking mentally deranged and unsafe people off the streets".
Trump used a similar line immediately after the dual shootings earlier this month at a Walmart in Texas and outside a bar in OH, saying that "mental illness and hatred pulls the trigger, not the gun".
"A lot of our conversation has to do with the fact that we have to open up institutions", Mr Trump added.
"We can't let these people be on the streets", he added.
"Instead, we urge you to support spending funds you have requested for the border wall, on other pressing needs such as proven initiatives that will address the threats of gun violence and white supremacist extremism in America", wrote Schumer and Leahy, who is the top Democrat on the Senate Appropriations Committee that oversees government outlays. "These people are mentally ill and we need to study that also".
Among Democrats, 87 percent blamed Trump to some degree, along with 50 percent of independent voters, but even among Republicans, more than one in five laid some of the blame for mass shootings at Trump's feet.
"They want to see something happen.it's very simple". He said Republicans agree "pretty much uniformly" that they "don't want to have insane people, risky people, really bad people having guns".
"Well, I'm afraid that if we came up with a good bill, I think the Democrats then might up it and then do things that can't be done and that the public wouldn't want done", Trump said.
He wouldn't say whether he supports universal background checks when asked, saying instead, "I support strong, meaningful background checks".
27 minors to leave Italy migrant ship: charity
Salvini rose to popularity on a hard-line anti-migrant stance and has repeatedly faced off with ships carrying rescued migrants. That scheme would take place once the migrants disembark in Algeciras, the Spanish government said in a statement.