Donald Trump blasted Malcolm Turnbull over a "dumb" refugee swap deal during a tense phone call, it has emerged, as the Australian Prime Minister was forced to deny that the US president slammed the phone down on him.

During a phone conversation on Saturday, Mr Trump reportedly told his Australian counterpart that he had spoken with four other world leaders that day and that “This was the worst call by far.”

The president, who reportedly blasted the Australian leader over a deal agreed with the Obama administration for the US to resettle some of the refugees held in remote Pacific island camps, abruptly ended Saturday's call, which was expected to last an hour, after just 25 minutes.