Obama: Soul-searching needed on high gun violence
President Barack Obama has said no other developed nation would tolerate the "off the charts" level of gun violence plaguing the United States.
At the White House, Mr Obama said the US' firm resistance to "basic" new gun controls was his "biggest frustration".
"The country has to do some soul-searching about this," Mr Obama said.
The nation has experienced a spate of mass shootings in recent years, at schools, universities and places of work, in addition to street crime.
In a White House forum with the founder and chief executive officer of social media site Tumblr, David Karp, Mr Obama took a question on gun control following word of a school shooting in Oregon which claimed two lives.
"We kill each other in these... mass shootings at rates that are exponentially higher than any place else," Mr Obama said.
"This is becoming the norm. And we take it for granted in ways that, as a parent, are terrifying to me. Right now, it's not even possible to get even the mildest restrictions through Congress... We should be ashamed of that."
Answering gun rights supporters who say America's violence stems from mental health issues rather than the prevalence of firearms, Mr Obama said, "You know, the United States does not have a monopoly on crazy people. It's not the only country that has psychosis."
Mr Obama's push for stricter gun control laws - particularly after the 2012 mass shooting at Sandy Hook Elementary school in Newtown, Connecticut - has stalled under stiff opposition from the powerful gun lobby, notably the National Rifle Association.
'Fundamental' shift needed
Following that massacre, in which 20 young children and six educators were murdered, Mr Obama proposed several federal gun control measures, including tightening the background check system to make it harder for convicted criminals to buy guns, but Congress, especially the opposition Republicans, blocked them.
He has continued to press Congress for further restrictions, although sceptics note that if the murder of 20 children failed to goad Congress to action, it is unclear what could.
"If public opinion does not demand change in Congress, it will not change," Mr Obama said on Tuesday.
"And until that changes, until there is a fundamental shift in public opinion in which people say, enough, this is not acceptable... sadly, not that much is going to change."
In the three days prior to Mr Obama's remarks, a man killed one person and wounded three others at a university campus in Seattle, a husband and wife team of attackers shot dead two police officers and a bystander in Las Vegas, and a gunman killed a high school student in a town in Oregon and then was himself shot dead.