Joe Biden has tested positive for Covid-19 and is suffering mild symptoms, the White House has said.

Karine Jean-Pierre, his press secretary, said the president is vaccinated and boosted. He has had Covid twice before.

Mr Biden, 81, was seen earlier on Wednesday visiting supporters in Las Vegas and speaking at an event. He has cancelled a campaign speech in the city tonight.

The illness comes as he faces increasing pressure to step aside because of his age following a poor debate performance at the end of June.

This is a developing story.