(Image Credit: ABC News)

In the wake of what he called the "slaughter of innocents" at Sandy Hook Elementary School, New York City Mayor Michael Bloomberg called on President Obama and Congress to make gun control their "first order of business."

"This is an outrage. We are killing each other and we're the only industrialized country in the world doing it," Bloomberg said at a press conference, surrounded by 34 people whose lives had been touched by gun violence.

The number of people chosen to stand with the mayor was symbolic, since he said 34 people are killed every day, on average, by guns in the United States.

"What happened at Sandy Hook Elementary School sadly was no aberration," he said, adding that by the end of the next presidential term, 48,000 Americans will be killed by guns.

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Bloomberg, who is the co-chair of Mayors Against Illegal Guns, a group of more than 700 mayors dedicated to getting illegal guns out of the hands of criminals, called on Congress and the president adopt "common-sense measures" to reduce gun violence.

First on the agenda, Bloomberg said, is to require background checks on private sales of firearms. He called the process "neither onerous or intrusive" but a matter of making sure guns aren't falling into the wrong hands.

Bloomberg also called for an "enforceable and effective assault weapons ban" to be passed, including the banning of high-capacity magazines, which are designed to kill people.

Finally, he asked that Congress and President Obama begin work today to make gun trafficking a felony.

Bloomberg said his call to action will be accompanied by 34 videos made by people affected by gun violence. They will be delivered to the new Congress in January. Each video ends with the same call to action: "I demand a plan."

"Words alone cannot heal our nation. Only action can do that. Gun violence is a national epidemic," Bloomberg said.

"I demand a plan. The time for talk is over."