President Donald Trump delivered a speech to a large crowd of more than 1,000 people on Thursday, as he formally accepted the Republican Party's presidential nomination on the South Lawn of the White House.

Photos show audience members close to each other, with few wearing masks. Chairs were placed about a foot apart.

The US has recorded the most deaths and cases in the coronavirus pandemic, and President Trump's response has been heavily criticised.

He did not mention the US death toll of more than 180,000 people in his speech but described Covid-19 as a "powerful invisible enemy".

He pledged America would "produce a vaccine before the end of the year, or maybe even sooner.” Experts say such a target is highly ambitious, and could involve cutting corners in terms of research and testing.

The Trump campaign said the Republican National Convention (RNC) worked with a private medical company to institute "proper protocols" for the White House event.