Joined by relatives of the victims of gun violence, U.S. President Barack Obama on Wednesday (April 17) angrily blamed politics for the failure of gun control legislation and urged voters to send a message at the ballot box that they want stronger gun laws.

"There were no coherent arguments as to why we wouldn't do this. It came down to politics," Obama said, flanked by relatives of the victims of recent mass shootings, some of whom wept during the president's comments.

"All in all this was a pretty shameful day for Washington but this effort is not over," he said.

The U.S. Senate on Wednesday rejected a bipartisan plan to expand background checks for gun buyers, despite emotional pleas from families of victims of the Newtown, Connecticut shooting and broad public support nationwide. The plan to extend background checks to online and gun-show sales failed on a 54-46 vote, six short of the 60-vote hurdle needed to clear the Senate.

"A minority in the United States Senate decided it wasn't worth it. They blocked common-sense gun reforms even while these families looked on from the Senate gallery," Obama said.

Obama said that this was "just round one".

"I believe we're going to be able to get this done. Sooner or later, we are going to get this right," he said. "The memories of these children demand it. And so do the American people."

The votes were the culmination of weeks of intense negotiations and lobbying over Obama's proposed gun restrictions. The defeat of the background checks amendment could doom the biggest package of gun legislation Congress has considered in two decades.

Presented by Adam Justice