US President Donald Trump has mild symptoms of Covid-19 after he and his wife Melania tested positive for the coronavirus, the White House says.

Mr Trump's chief of staff said the president was "on the job" and "in good spirits", adding that he expected him to make a quick recovery.

The news comes just over a month before presidential elections, where he will face Democratic challenger Joe Biden.

Mr Biden himself and his wife Jill tested negative on Friday.

"I hope this serves as a reminder," he tweeted after the result. "Wear a mask, keep social distance, and wash your hands."

Mr Biden's staff said he would travel to Michigan on Friday as planned for several campaign events.

Other close members of Mr Trump's family have tested negative.

Officials said the process of tracking all the president's contacts in recent days was ongoing, adding that Mr Trump was considering how he might address the nation or otherwise communicate with the American people on Friday.

But he pulled out of a video conference call with vulnerable seniors scheduled for Friday, leaving Vice-President Mike Pence to chair the meeting.

On Thursday, the first couple said they intended to self-isolate after one of Mr Trump's closest aides, Hope Hicks, tested positive. Soon afterwards, they too received positive test results.

But there has been criticism of Mr Trump's decision to go to a fundraiser attended by dozens of people in New Jersey on Thursday, apparently when officials already knew about Ms Hicks's symptoms.

Ms Hicks, 31, travelled with Mr Trump on Air Force One to the first presidential TV debate with Mr Biden in Ohio on Tuesday. Some of Mr Trump's family members who attended the debate were seen not wearing masks.

Mr Trump has mostly spurned mask-wearing and has often been pictured not socially distanced with aides or others during official engagements.

The coronavirus has infected more than 7.2 million Americans, killing more than 200,000 of them. (BBC)

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