Trump too dangerous to be entrusted with nuclear codes: Hillary

Lambasting presumptive Republican presidential nominee Donald Trump's ability to lead the United States, Democratic frontrunner Hillary Clinton branded the former "too dangerous and unstable to be entrusted with nuclear codes", and warned of an economic crisis if he were to reach the White House.

Clinton, former secretary of state, made the assault while addressing a crowd in San Diego on Thursday.

"Donald Trump's ideas aren't just different, they're dangerously incoherent. They're not even really ideas, just a series of bizarre rants, personal feuds and outright lies. He is not just unprepared. He is temperamentally unfit to hold an office that requires knowledge, stability and immense responsibility," the Guardian quoted her as saying.

Clinton said the New York billionaire's presidency could lead to "catastrophe".

"He should not have the nuclear codes, because it's very easy to imagine Donald Trump leading us into a war just because someone got under his very thin skin. We cannot let him roll the dice with America," she said.

She made a tacit plea to independents and moderate Republicans, saying Trump denigrated U.S. power even when Ronald Reagan was president.

"We can't put the security of our children and grandchildren in Donald Trump's hands," she said adding, "I believe he will take our country down a truly dangerous path."

Meanwhile, Hillary is battling to fend off a surging Bernie Sanders campaign that threatens to snatch victory in California's June 7 Democratic primary.

According to the Associated Press, she is just 71 delegates shy of the 2,383 needed to clinch the Democratic nomination.