This post has been updated.
Obama said the country needs to "do some soul searching" about a culture where mass shootings have become pervasive.
"We're the only developed country on Earth where this happens," Obama said. "And it happens now once a week. And it's a one-day story. There's no place else like this."
Obama said he respects gun rights, but said it "makes no sense" that a bill calling for rigorous background checks to buy semi-automatic weapons did not pass Congress. He said it is possible to respect the Second Amendment, let responsible people own guns and still support restrictions that may help curb gun violence.
Obama used Australia as an example of a country that had a mass shooting and enacted strict gun laws. There has not been a mass shooting in the country since, he said.
"I mean, our levels of gun violence are off the charts," Obama said. "There's no advanced, developed country on Earth that would put up with this."
Obama continually pushed Congress, saying that despite taking a number of executive actions he cannot completely turn the tide on gun violence. Obama called on the public to lobby Congress to demand change.
"And most members of Congress -- and I have to say to some degree this is bipartisan -- are terrified of the NRA. The combination of, you know, the NRA and gun manufacturers are very well financed and have the capacity to move votes in local elections and congressional elections. And so if you're running for office right now, that's where you feel the heat," Obama said.
Obama said guns themselves and the culture surrounding them, not only mental health issues, play a big part in violence.
"A lot of people will say that, you know, “well, this is a mental health problem. You know, it's not a gun problem.” You know, the United States does not have a monopoly on crazy people. It's not the only country that has psychosis," Obama said. "And yet, we kill each other in these mass shootings at rates that are exponentially higher than any place else. Well, what's the difference? The difference is, is that these guys can stack up a bunch of ammunition in their houses. And that's sort of par for the course."
Obama's remarks came hours after a gunman killed a student and wounded a teacher at a high school in Troutdale, Ore. Authorities said the gunman acted alone and is dead.
"This is becoming the norm," Obama said, in ways that "as a parent, are terrifying to me."
There have been at least 74 school shootings since a gunman killed 20 children and six adults in a Newtown, Conn., elementary school in December 2012.
Obama spoke about Richard Martinez, whose son was one of six people killed in a rampage last month in Santa Barbara, Calif. Martinez has lashed out against "craven" politicians and the National Rifle Association and called on Obama and Congress to pass stricter gun-control laws.
"As a father myself, I just ... could not understand the pain he must be going through and just the primal scream that he gave out. Why aren't we doing something about this?" Obama said. "And I will tell you that I have been in Washington for a while now and most things don't surprise me. The fact that 20 six-year-olds were gunned down in the most violent fashion possible and this town couldn't do anything about it was stunning to me. And so the question then becomes, what can we do about it?"