(CNN) — Vice President Joe Biden reassured leading gun control groups Thursday that the administration remains committed to pushing an expansion of background checks for gun purchases through Congress, according to one of the event's attendees.
Biden, who has led the administration's efforts on gun control in the wake of the shooting in Newtown, Connecticut, told the meeting of about 15 participants that despite last week's defeat of a bi-partisan measure in the Senate to expand checks at gun shows and online sales, that this was just the beginning.
"He was delivering a charge to us" to stay engaged Pia Carusone, executive director of the group formed by former congresswoman Gabby Giffords and her husband Mark Kelly, told CNN summarizing the vice president's message. "He was determined."
The meeting included that group, Americans for Responsible Solutions, as well as Mayors Against Illegal Guns (formed by New York Mayor Michael Bloomberg), the Brady Campaign to Prevent Gun Violence, Center for American Progress, Moms Demand Action and representatives of law enforcement.
The administration has said it is committed to continue to push Congress on the issue. Biden's office confirmed the meeting but would not provide further detail of his remarks.
"We all are in a period of discussion and figuring out what the best strategy is," Carusone said. "It is just clear there is a strong determination on the part of the administration and all of these various groups that this issue not go away."
In the wake of their loss, groups involved in the fight are trying to figure out ways to harness public support and build pressure on lawmakers citing polls showing about 90% of Americans supported the background checks expansion.
The Giffords/Kelly group went up with radio ads this week criticizing Ayotte and Senate Minority Leader Mitch McConnell over their votes opposing the background checks measure and one praising Sen. John McCain for his vote supporting it. Giffords also sent out an email to supporters asking them to pledge "to become a gun violence voter in 2014." She said: "If you're still angry about last week's vote, you are not alone. But it's up to us to do something about it, because if we don't act, no one will."
The advocacy organization formed by some of President Obama's former campaign aides, Organizing for Action, bought new online ads to run on news sites and key newspapers in the home states of 10 senators, nine Republican and one Democrat who voted against the background checks issue last week. The ads are tailored to each state, such as one for New Hampshire saying "Remind Senator (Kelly) Ayotte: you work for New Hampshire, not the gun lobby." Among the other senators the group is aiming its ads at are: Republicans Saxby Chambliss, Dan Coats, Ted Cruz, Jeff Flake and Rob Portman and Democrat Heidi Heitkamp.
Meanwhile, the National Rifle Association will be trying to marshal its members to keep up the pressure against some of the proposals at its annual convention next week in Houston. The group said it is expecting 70,000 attendees, which would be one of its largest conventions in its history. Among those speaking will be Republican Governors Rick Perry (Texas) and Bobby Jindal (Louisiana) as well as former Republican vice presidential nominee Sarah Palin, former Republican presidential candidate Rick Santorum and Senator Ted Cruz, R-Texas.