Most Americans plan to watch Biden-Trump presidential debate, finds poll

For 90 minutes on Thursday night, US President Joe Biden has the chance to show doubting Americans that, at age 81, he is capable of handling the rigours of another four-year term, when he faces off in a debate against Republican Donald TrumpTrumpTrump.

A strong showing could help neutralise those concerns and focus voter attention on policy issues. A weak performance could dampen fundraising and push Trump further ahead in the polls.

Both men are under scrutiny over their age and stamina. Trump is 78 and prone to making outlandish statements and mangling his sentences on the campaign trail.