Donald Trump, the presumptive Republican nominee, has said that President Barack Obama should “resign in disgrace” for failing to call the Orlando massacre "Islamic terrorism".

The businessman used the attack in which 50 people were shot dead as a chance to boast that he was "right on radical Islamic terrorism".

"Because our leaders are weak, I said this was going to happen - and it is only going to get worse," Mr Trump said in a statement. "I am trying to save lives and prevent the next terrorist attack. We can't afford to be politically correct anymore."

Mr Trump's campaign said he will address the attacks in a speech he already had scheduled to deliver on Monday addressing national security