Kevin McHale has branded actor Dean Cain a "pathetic loser" after he revealed he's signed up to join America's Immigration and Customs Enforcement (ICE) agency.

On Thursday, the former Glee star took to X/Twitter days after Cain, best known for playing Superman in Lois & Clark: The New Adventures of Superman, revealed that he was becoming an agent for the U.S. federal organisation.

"Look, I know the entertainment business is in shambles, but imagine being so out of work and desperate for attention (I would know) that you join ICE?" McHale, 37, wrote.

The actor added, "F**king pathetic loser."

Cain, 59, first announced his plans to join ICE on Tuesday in an Instagram video, which has since been met with backlash online.

"For those who don't know, I am a sworn law enforcement officer, as well as being a filmmaker. I felt it was important to join with our first responders to help secure the safety of all Americans," he said. "Not just talk about it - so I joined up. Here's your opportunity to join ICE."

The God's Not Dead actor then encouraged his followers to join ICE, insisting that the organisation protects America from "the worst of the worst".

"If you want to help save America, ICE is arresting the worst of the worst and removing them from America's streets," he said. "I like that, I voted for that. They need your help to protect our homeland and our families."

Cain subsequently explained his decision on the Fox News show Jesse Watters Primetime on Wednesday, saying, "This country was built on patriots stepping up, whether it was popular or not, and doing the right thing. I truly believe this is the right thing."