President Obama addressed the people of Newtown, Conn., Sunday night in a nationally televised speech in which he said the country needs to change to protect its children.

"This is our first task," he said. "Caring for our children. It's our first job. If we don't get that right, we don't get anything right. That's how as a society we will be judged. And by that measure, can we truly say, as a nation, that we're meeting our obligations? Can we honestly say that we're doing enough to keep our children -- all of them -- safe from harm?"

He continued: "I've been reflecting on this the last few days. And if we're honest with ourselves, the answer's no. We're not doing enough, and we will have to change."

He said this was the fourth time in his presidency "we have come together to comfort a grieving community torn about by mass shootings."

"We can't tolerate this anymore. These tragedies must end. And to end them we must change," he said. "No single law, no set of laws can eliminate evil from the world or prevent every senseless act of violence in our society but that can't be an excuse for inaction. Surely we can do better than this."

Though he didn't go into specifics, he pledged to use "whatever power this office holds" to prevent future mass killings. Obama also praised teachers and children who helped each other during the killing, which claimed 20 children and six adults.

"You are not alone," he said, saying the nation shared in the grief of a town that could have been any town.

He concluded by reading the names of each of the murdered children.

"God has called them all home," he said. "For those of us who remain, let us find the strength to carry on and make our country worthy of their memory."

Watch the speech: