Despite the failure of gun legislation in the Senate in April, Vice President Biden says the fight for expanded background checks and other gun reforms is not over. (The Washington Post)

Declaring that “we have not given up,” Vice President Biden warned Tuesday that lawmakers who opposed the Obama administration’s proposals to stem gun violence “will pay a political price.”

Biden appeared in a White House auditorium to announce that the administration has completed or made significant progress on nearly two dozen smaller-scale executive actions aimed at strengthening existing background checks, improving record-keeping, and providing schools and communities with emergency management plans.

The setting was the same, but the political dynamics far different than they were five months ago when Biden and President Obama used the same auditorium to propose the most expansive overhaul of the nation’s gun laws in generations. They hoped to prohibit assault weapons and high-capacity ammunition magazines and to require that every gun buyer undergo a background check.

But with their agenda blocked on Capitol Hill, Biden acknowledged that the progress report on the administration’s actions — he said 21 of 23 executive actions rolled out in January have been nearly completed — would not be enough to make serious headway in the fight against gun violence.

“As proud as the president and I am of progress we’ve made, we need Congress to act,” Biden said, speaking to an audience that included Attorney General Eric H. Holder Jr. and Homeland Security Secretary Janet Napolitano. “We need everyone in the country to know the fight is not over. Far from it. . . . I assure you one thing each of us says to our colleagues about the votes: ‘The country has changed. You will pay a political price for not getting engaged and dealing with gun safety.’ ”

Gun-control advocates described the administrative actions as baby steps that would do relatively little to prevent the next mass shooting.

“What can be accomplished through executive action is real and necessary, but not sufficient,” said Mark Glaze, executive director of Mayors Against Illegal Guns.

“If all that comes out of this once-in-a-generation debate is teaching kids how to duck and cover during a mass shooting, some members of Congress are going to have a lot to explain when it happens. And it will happen,” added Glaze, whose group is financed and led by New York Mayor Michael R. Bloomberg (I).

In the weeks since the Senate blocked the administration’s gun proposals in mid-April — including a background-check compromise that polls showed 90 percent of Americans supported — Obama and Biden have rarely mentioned gun violence.

With his speech Tuesday, though, Biden renewed the call for universal background checks and reminded the public that gun control remains on the administration’s agenda despite the defeat.

“Because of the invocation of a rule, a perverted filibuster rule requiring 60 votes for everything, we lost,” Biden said of the Senate vote on universal background checks. Since the mass shooting at Sandy Hook Elementary School in Newtown, Conn., in December, he said, “more people have died at the end of a gun than we have lost in Afghanistan. Pretty astounding. And Iraq. That’s no way to run a country. The country knows it. They know we can do something about it.”

National Rifle Association spokesman Andrew Arulanandam said the White House is sidestepping Congress and “the will of the people” with its unilateral executive actions.

“It is clear that the reason the White House is resorting to doing executive actions and administrative actions is because they are trying to bypass the will of the people and circumvent Congress,” he said.

The executive actions were the product of Biden’s task force, which reviewed ways to stem gun violence after the Newtown massacre, in which 20 children and six adults were killed.

Several of the actions were bureaucratic steps designed to strengthen the existing background-check system, including making federal agencies provide relevant criminal records and improving incentives for states to share information with the system.

Other steps could help empower law enforcement, including enhancing data to trace firearms and allowing police to run background checks on released suspects before returning seized guns to them.

In addition, Obama has directed the Centers for Disease Control and Prevention to research the causes and prevention of gun crimes, including links between video games, media images and violence, officials said.

Biden held up several documents, which he described as detailed emergency management plans that would help communities and schools prepare for mass shootings or attacks.

“I personally was getting calls from around the country: ‘Joe, what do we do if anything remotely similar to what happened at Sandy Hook happens in our community?’ ”

Pia Carusone, executive director of Americans for Responsible Solutions, a group founded by former congresswoman Gabrielle Giffords (D-Ariz.), pointed to new laws in some states, such as Delaware and Colorado, which have toughened firearm restrictions.

“There’s a lot that can be done to make our communities safer, some of which can be done at the executive level and some of which can be done at the legislative level,” Carusone said. “In the absence of any federal action legislatively, there’s been a lot of good work that’s been done at the state level.”

White House aides and gun-control advocates hope the Senate will reconsider the measure this summer or fall. But a senior administration official would not disclose whether any progress had been made on the legislative front since the April vote, or detail any conversations Obama, Biden or other White House officials may have had with key senators.

Biden was introduced Tuesday by Stephen Barton, who was struck twice during the mass shooting in a movie theater in Aurora, Colo., last year.

“If you want reason for optimism, you’re looking at it,” Biden said of Barton. Turning to him, the vice president said, “I look forward to working with you and finishing the job.”