After the school shooting in Newtown, Conn., in December, Obama asked Biden to work on measures to curb gun violence.
(Read More: Obama Names Biden to Head Gun-Control Effort)
On Thursday, Biden will meet with pro-gun groups including the National Rifle Association, which has pledged to resist new gun-control measures proposed in the wake of the Newton, CT, school shooting last year. Instead, the NRA has argued that armed guards should be placed in schools to deter or stop school shooters.
(Read More: NRA's LaPierre Calls for Cops in Schools)
Biden will also meet with corporations and other special interest groups.
Wal-Mart Stores, which sells guns in more than 1,000 stores in the United States, had initially said it wouldn't send a representative to a gun-control meeting with Biden but then, very quickly Wednesday, reversed course and said it would send "an appropriate representative" to the meeting.
"Knowing our senior leaders could not be in Washington this week, we spoke in advance with the vice president's office to share our perspective," Wal-Mart said in a statement. "We underestimated the expectation to attend the meeting on Thursday in person, so we are sending an appropriate representative to participate."
(Read More: Gun Laws Have 'More Holes Than Swiss Cheese')
But the NRA and Wal-Mart will be facing an administration that has said it is determined to take action in the wake of that shooting and, which has already heard emotional pleas for new gun-safety regulations Wednesday from victims of horrific attacks.
One by one, gun-violence victims emerged from the White House meeting and told reporters their names and those of relatives who had been killed by guns. Lonni Phillips said his stepdaughter Jessica Ghawi was killed in the Aurora, CO, shooting last year. Annette Nance-Holt said her 16-year-old son was shot on a bus in Chicago in 2007. Colin Goddard said he'd been shot four times during the Virginia Tech shooting in 2007. He said he was one of just seven in his classroom of 17 people to survive the shooting. Each one said the experience had driven them to advocate for gun control and participate in today's meeting.
(Read More: Time for Tougher Gun Laws: Sen. Manchin, NRA Supporter)
While Biden mentioned that Obama was prepared to invoke an executive order, it was unclear what any kind of executive order might be.
"Decisions have not been made," White House spokesman Jay Carney said.
And, while executive order implies that the president would be excluding Congress, at least some component of the president's plan would have to go to Capitol Hill. "Legislative action is certainly part of this," Carney said.
Though, that would likely touch off one of the biggest political fights of the year.
-- Reuters contributed to this article