Joe Biden's under increasing pressure to stand aside as the Democratic presidential candidate as Donald Trump prepares to formally accept the Republican nomination. 

Sources have told the Associated Press that both Barack Obama and Nancy Pelosi have privately called for Biden to step aside. 

It comes as the US President continues to isolate with Covid. 

Meanwhile, Marco Rubio's former Chief of Staff Matt Terrill told Ryan Bridge Trump will address the Republican National Convention this afternoon, calling for unity six days after he survived an assassination attempt. 

He says a big theme for tonight's speech will be about unity not only for the Republican Party, but for the whole country. 

That speech is expected to start about 2pm. 

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