The party was working within the parameters set before us by state and local guidelines regarding the number of people who can attend events , the spokeswoman said on Saturday.
A Republican National Convention spokeswoman gave coronavirus health guidelines as the reason, the BBC reported.
The party was "working within the parameters set before us by state and local guidelines regarding the number of people who can attend events", the spokeswoman said on Saturday.
The 336 party delegates will meet on August 24 in the city of Charlotte, North Carolina to formally renominate Trump.
They will cast proxy votes for some 2,500 official delegates.
Trump is the party's sole remaining nominee, and his renomination will officially launch his re-election bid.
Saturday's decision marks a significant change for the convention, which historically has worked to draw media attention to spread party messaging to the public, said the BBC report.
Trump had switched the location of the convention to Jacksonville, Florida, after the Democratic governor of North Carolina insisted in May on limiting the crowd size at the convention, on the grounds of social distancing.
But he later scrapped the Florida convention, blaming the state's coronavirus "flare-up".