"No major party nominee in the history of the United States of America ... has known less or been less prepared to deal with our national security than Donald Trump, and what absolutely amazes me, what absolutely amazes me, that he doesn't seem to want to learn it," Biden said in his hometown of Scranton, Pennsylvania, as he campaigned with Hillary Clinton for the first time.
The vice president said the Republican presidential nominee is "not qualified" to know the nuclear codes and added he would have stopped his late son, Beau, who was in the Delaware Army National Guard, from heading into a conflict zone if Trump had become president while he was alive.
"He can't be trusted!" Biden said. "My son Beau served for a year in a Iraq, came back a highly decorated soldier. I must tell you, no I must tell you, had Donald Trump been president I would have thrown my body in front of him. No, I really mean it. To keep him from going if the judgment was based on Trump's decision."
Biden also turned to some of Trump's recent controversial foreign policy statements, criticizing him for suggesting Russia should find and release Hillary Clinton's private e-mails.
"This guy's shame has no limits. He's even gone so far as to ask Putin and Russia to conduct cyber attacks against the United States of America," he said. "No, no, even if he is joking -- which he's not -- even if he's joking what an outrageous thing to say."
The vice president went on to take on Trump for his suggestion that President Obama was the founder of ISIS, calling it an "outrageous" and "dangerous statement."
Biden then argued Clinton was better suited to serve as commander-in-chief. "Hillary has forgotten more about American policy than Trump and his entire -- not exaggerating -- his entire team will ever understand," he said.