Democratic presidential candidate Hillary Clinton has sharply criticised the likely Republican nominee Donald Trump as "not just unprepared" to be president but "temperamentally unfit" to hold the office.

Clinton blasted the billionaire businessman from New York for failing to outline a coherent foreign policy doctrine, adding that he poses a threat to US alliances abroad.

"Donald Trump’s ideas aren’t just different - they are dangerously incoherent," Clinton said. "They’re not really ideas, just a series of bizarre rants, personal feuds and outright lies."

Al Jazeera's Alan Fisher reports from Washington DC.

Source: Al Jazeera