Former Vice President Mike Pence is calling for expedited executions of criminals convicted of mass shootings in the U.S., saying “justice delayed is justice denied.”

During his appearance Friday at the annual National Rifle Association Institute for Legislative Action leadership forum in Indianapolis, Mr. Pence, a likely 2024 GOP presidential candidate, said the federal government must do more to confront crime and deal with mental illness if it is serious about addressing gun violence.

Mr. Pence said too many mass shooters “languish in prison for years.”

“I think the time has come for a federal death penalty statute with an expedited appeal that would ensure that those who engage in mass shootings in this country face execution in months, not years,” he said.

Mr. Pence also said leaders should rally behind the push to provide taxpayer funds to place armed resource officers in “every public and private school in America” and to build more facilities for the mentally ill.

“Ignoring the motivations of the trans activist who killed three children and three adults at that Christian school in Nashville, and the ‘mental health challenges’ of the man who killed five people and injured eight others in Louisville, President Biden and the Democrats have returned to the same tired arguments about gun control and confiscation,” Mr. Pence said.

“But we don’t need gun control — we need crime control,” he said. “We don’t need lectures about the liberties of law-abiding citizens. We need solutions to protect our kids.”

Mr. Pence is sharing the spotlight at the NRA convention with former President Donald Trump, and fellow 2024 presidential contenders: former Arkansas Gov. Asa Hutchinson, and businessman Vivek Ramaswamy.

Former ambassador to the United Nations Nikki Haley, another presidential contender, is slated to address the conference via video message.

Gov. Ron DeSantis of Florida and Sen. Tim Scott of South Carolina, a pair of likely 2024 contenders, also are scheduled to address the crowd remotely

Mr. Pence said the “elites” are trying to push their left-wing agenda on Americans and strip away their rights, including their right to keep and bear arms.

He said as “long as there is breath in my lungs” he will fight to protect the Second Amendment, and said Democrats’ soft-on-crime approach is not working.

“So I say to Joe Biden and the gun control extremists, ‘Give up your pipe dreams of gun confiscation in this free society, stop endangering our lives with gun bans, and stop trampling on the God-given rights of the American people,’” he said.

Democrats looked to put Mr. Trump and fellow Republicans on defense over guns ahead of the NRA convention.

Jaime Harrison, chair of the Democratic National Committee, and Sen. Chris Murphy of Connecticut said in a conference call Thursday that Republicans were siding with the party’s radical base, and turning their backs on the families and children who have suffered from gun violence.

Mr. Harrison said the appearance of Mr. Trump and other Republicans is “indefensible” following the recent shooting in Nashville and Louisville.

“The Republican Party continues to put the gun industry and the gunmakers before the safety of our kids and our families,” Mr. Murphy said. “It’s extraordinary, it’s heartbreaking, and it’s infuriating.”

Mr. Murphy has been pushing for stricter gun laws since the 2012 shooting at Sandy Hook Elementary School shooting in Newtown, Connecticut, that left 26 people dead, including 20 children.

“Every significant national Republican – every Republican that’s throwing their hat in the ring to run for president – is showing up this weekend to pledge their undying loyalty to the NRA and the gun lobby literally days after patrons at banks and little kids at elementary schools were gunned down in cold blood because of a set of laws midwifed by the NRA that leaves our kids and families exposed to epidemic rates of gun violence,” he said.