Democratic White House hopeful Joe Biden on Monday called for an end to "lawlessness" and violence in protest-hit US cities, while blaming Donald Trump's "toxic" presidency for fueling the unrest that has left several people dead. "Looting is not protesting, setting fires is not protesting. None of this is protesting. It's lawlessness, plain and simple, and those who do it should be prosecuted," Biden said in a speech in Pittsburgh -- at which he also charged that Trump was "part of the problem." "Our current president wants you to live in fear," charged the 77-year-old Democrat. "He advertises himself as a figure of order. He isn't. And he's not been part of the solution thus far. He's part of the problem." "Donald Trump has been a toxic presence in our nation for four years." mlm/ec