Donald Trump has prompted outrage online Monday with comments suggesting that PTSD sufferers are somehow not "strong."

None were more offended than Vice President Joe Biden, who brought up the issue during a campaign rally for Hillary Clinton in Florida.

SEE ALSO: What Donald Trump got wrong about PTSD

"Where in the hell is he from?" he asked, before telling the audience: "This is deadly earnest."

Biden then spoke about his son serving in Iraq and revealed he gets a daily update from the Department of Defense on troop deaths in Iraq and Afghanistan.

"Every one of those warriors left behind a family ... for us," he said, before discussing the numbers of soldiers "coming home with unseen wounds."

He then slammed Trump for being "so thoroughly, completely uninformed."