People who celebrate the killing of conservative influencer Charlie Kirk should be held accountable, US Vice-President JD Vance has said.

"Call them out, and hell, call their employer," Vance said as he guest-hosted an episode of the Charlie Kirk Show. "We don't believe in political violence, but we do believe in civility."

Pilots, medical professionals, teachers and one Secret Service employee are among those who have been suspended or sacked for social media posts that were deemed inappropriate about Kirk's death.

Critics have argued the firings threaten free speech and employee protections, although US companies have wide latitude to terminate employees.

Vance's comments aired on Monday in an episode of the Charlie Kirk Show, a daily podcast that Kirk hosted before he was shot in the neck last Wednesday while hosting a debate at Utah Valley University.

In the episode, the vice-president said that left-wing Americans "are much likelier to defend and celebrate political violence", and added that "there is no civility in the celebration of political assassination".

A recent YouGov poll found liberal Americans were more likely than conservatives to defend feeling joy about the deaths of political opponents.

Vance's remarks come as other Republican US lawmakers echoed calls for those publicly celebrating Kirk's death to be punished.

"I will demand their firing, defunding, and license revocation," said Florida congressman Randy Fine in a post on X on Sunday, as he called for such people to "be thrown out of civil society".

South Carolina congresswoman Nancy Mace urged the Department of Education to "cut off every dime to any school or university" that refuses to retaliate against employees making insensitive posts about Kirk.

Kirk, a devout Christian, professed viewpoints on gender, race and abortion that drew backlash from many liberals, especially on the campuses he toured.

In some cases, those who took to social media to gloat over his death or post comments that caused offence have been fired or placed on leave by employers.

Among them is Anthony Pough, a US Secret Service employee who wrote on Facebook that Kirk "spewed hate and racism on his show... at the end of the day, you answer to GOD, and speak things into existence".

He has had his security clearance revoked.

Secret Service Director Sean Curran wrote in a memo to staff that politically motivated attacks are on the rise and members of the protective detail should not be exacerbating the issue.

"The men and women of the Secret Service must be focused on being the solution, not adding to the problem," Curran wrote.

Americans employed by private companies have also come under scrutiny. Office Depot fired employees at a Michigan branch after a viral video showed staff refusing to print posters for a Kirk vigil, the company confirmed to the BBC in a statement.

A spokesperson for Office Depot said the employees' behaviour "was completely unacceptable and insensitive", and violated the company's policies.

Professors and journalists, too, are facing punishment for their comments, provoking a debate over so-called cancel culture.

Karen Attiah, a long-time columnist for the Washington Post, wrote in a Substack post that the newspaper had fired her after a series of posts she made on social media platform Bluesky following Kirk's death.

In South Carolina, Clemson University said in a statement on Monday that it had fired one employee and placed two professors on leave for what it called "inappropriate" social media posts related to Kirk's killing.

The repercussions have reached beyond the US.

In Canada, University of Toronto professor Ruth Marshall was placed on leave after appearing to write in a social media post that "shooting is honestly too good for so many of you fascists".

US employers generally have broad discretion to fire workers for any reason, as most staff are hired under "at-will" contracts.

Steven Collis, a law professor at the University of Texas Austin, said the right to free speech under the US Constitution does not cover private employers.

Rather, it applies to government actions restricting citizens' free speech, he said.

But Risa Lieberwitz, head of the Worker Institute at Cornell University, said public figures could be infringing on free speech rights if they call for accountability over posts about Kirk.

She said the spate of firings was not surprising, given the current heated political rhetoric in the US.

"I think it reflects the kind of fear that exists now in the United States from retaliation by the Trump administration for not adhering to their political agenda," she said.

Some have criticised the firings, like the American Association of University Professors, who said in a statement on Monday that academic freedom should be protected and "not curtailed under political pressure".