Obama promises new gun proposals

"I am also betting that the majority, the vast majority, of responsible law-abiding gun owners would be some of the first to say that we should be able to keep an irresponsible, law-breaking few from buying a weapon of war," he said.

He also challenged the National Rifle Association to do "some self-reflection." The gun lobby is a powerful political force, particularly in Republican primaries, and previously has worked to unseat lawmakers who back gun control measures.

The NRA, in its first statements since the shooting, pledged Tuesday to offer "meaningful contributions to help make sure this never happens again."

The Biden-led task force will also explore ways to improve mental health resources and address ways to create a culture that doesn't promote violence. The departments of Justice, Education, Health and Human Services, and Homeland Security, along with outside groups and lawmakers, will all be part of the process.

Biden will start his discussions Thursday when he meets with law enforcement officers from around the country. He'll be joined by Attorney General Eric Holder, Education Secretary Arne Duncan, Homeland Security Secretary Janet Napolitano and Health and Human Services Secretary Kathleen Sebelius.

Biden's prominent role could be an asset for the White House in getting gun legislation through Congress. The vice president spent decades in the Senate and has been called on by Obama before to use his long-standing relationships with lawmakers to build support for White House measures.

The vice president also brings to the effort a long history of working on gun control issues, having chaired the Senate Judiciary Committee and leading the original effort to ban assault weapons. The ban expired in 2004, but Sen. Dianne Feinstein, D-Calif., says she plans to bring it back for a vote early next year.