London Mayor Boris Johnson said that Russian President Vladimir Putin should "strip to the waist" and take part in the Olympic judo event.
Mr Putin, who holds a black belt in the martial art, will visit Downing Street before heading to the Olympic Park.
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The Democratic presidential candidate may also have shown his cards on his choice of running mate.
The US president also shared a post on Twitter accusing Dr Anthony Fauci of misleading the public over hydroxychloroquine.
Fears over an impending second wave of coronavirus dominates Wednesday’s front pages.