US President Donald Trump has refused to take part in a virtual TV debate with his Democratic rival Joe Biden.
The commission organizing the debate in Miami on 15 October had earlier said it would have to take place remotely.
It made the decision after Mr Trump was treated for Covid-19. The president said he would not waste his time on a move designed to “protect” his rival.
Mr Biden’s campaign said Mr Trump was trying to evade accountability on his “failures on Covid and the economy”.
Both teams later appeared to agree on 22 October as a rescheduled date, although what form the debate would take is unclear.
The first presidential debate on 30 September had descended into insults and interruptions. The vice-presidential debate, held on Wednesday night between Mike Pence and Kamala Harris, was a far more measured affair.
The US election will be held on 3 November. Latest opinion polls suggest Mr Biden has a high single digit lead nationally, but the outcome is often decided in battleground states where the races can be much closer.
His comments during a phone-in interview with Fox Business Channel on Thursday touched on a number of key matters, including his health and the possibility of movement towards a stimulus package for the economy. But it was his comments on the debate format that drew most attention.
Mr Trump said:
“I’m not gonna waste my time on a personal debate. Sit behind a computer, ridiculous. They cut you off… I’m not doing a virtual debate.”
He also described the moderator of the Miami debate – the political editor of the cable and satellite television network C-SPAN, Steve Scully – as a “never Trumper”.
A statement from Trump campaign manager Bill Stepien, who had also previously tested positive for Covid, said the decision of the commission to “rush to Joe Biden’s defence” was “pathetic” and Mr Trump would have posted “multiple negative tests” before the debate.
He said Mr Trump would hold a rally instead.
On his health, Mr Trump said: “I’m back because I’m a perfect physical specimen.” He said he had stopped taking most “therapeutics” but was still taking steroids and would be tested for Covid again “soon”.
But although his doctor has said he now has no symptoms, questions still remain about when the president first became infected and whether he could still be contagious.
And although the names of many people who have interacted with the president and tested positive are now known, it remains unclear just how many were exposed at the White House. New Covid safety measures are in place there.
Mr Trump said on Thursday that “somebody got in and people got infected” but gave no more details.