US Vice President Joe Biden has denounced Republican presidential nominee Donald Trump as a deadly choice for America�s future.

�No major-party nominee in the history of this nation has ever known less or has been less prepared to deal with our national security,� Biden said on Wednesday night at the Wells Fargo Center for the Democratic National Convention.

�Donald Trump and all his rhetoric would literally make us less safe,� he added.

Biden's rebuke came just hours after Trump reportedly called on Russia to hack into Democratic presidential nominee Hillary Clinton�s email server to obtain unpublished emails.

Citing Trump�s signature line from his TV show, "The Apprentice,� Biden said, "His lack of empathy and compassion can be summed up in a phrase I suspect he's most proud of having made famous: 'You're fired.��

"How can there be pleasure in saying 'You're fired'? He's trying to tell us he cares about the middle class? Give me a break. That's a bunch of malarkey!� Biden said.

Describing himself as �middle-class Joe,� Biden criticized Trump over his claims that he understands the problems of the American middle class.

�This guy doesn�t have a clue about the middle class. Not a clue,� Biden said. �Actually, he has no clue, period.�

Biden, who once was tipped to be Clinton�s primary rival, avoided to call Clinton a friend and did not narrate any anecdotes � like several other speakers did -- about their 30-year working relationship.

�Everybody knows she's smart. Everybody knows she's tough. But I know what she's passionate about. I know Hillary. Hillary understands. Hillary gets it,� Biden said.

�There is only one person in this race who will be there, who has always been there for you, and that's Hillary Clinton's life story. It's not just who she is; it's her life story. She's always there. She's always been there,� he said.

Republicans had long speculated that the federal investigation into Clinton's use of a private email server while she was US secretary of state could result in criminal charges against her, forcing Biden to seek the nomination.

Biden, however, said repeatedly he was not interested in running for the White House, citing the death of his son Beau last year as the main reason.

Clinton is still facing a potential indictment as the Federal Bureau of Investigation (FBI) investigates the email controversy.

More than 2,000 emails sent and received by Clinton while working as the top US diplomat between 2009 and 2013 include classified information, which the government bans from being handled outside secure, government-controlled channels.

By Press TV