Obama: Gun control failure is biggest frustration

WASHINGTON (AP) - President Barack Obama says his biggest frustration so far as president is that American society hasn't been willing to take steps to strengthen gun control.

Obama is reflecting on frequent mass shootings during a question-and-answer session on social media site Tumblr. He says the U.S. should be ashamed.

Obama says there's no place else in the world where mass shootings are a once-a-week occurrence. He says the country must do some soul-searching.

Obama says he respects gun rights. But he says he was stunned after the Newtown school shooting that Washington couldn't even pass universal background checks. He's citing the political strength of the National Rifle Association and gun manufacturers.

Obama says until there's public opinion a fundamental shifts, the problem won't change. He says as a parent, that's terrifying.