The Tesla chief executive said the first batch of donated machines would be delivered later on Friday.

The ventilators were purchased from US government-approved manufacturers in China.

The mayor of New York City Bill de Blasio thanked Mr Musk on Twitter writing "We're deeply grateful."

"We need every ventilator we can get our hands on these next few weeks to save lives," he tweeted.

The ventilators will be donated to hospitals in New York City and across New York state.

New York has the highest number of cases of Covid-19 in the US. As of Friday the governor said 519 people in the state had died from the disease.

On Thursday, the US officially became the country with the most confirmed cases of Covid-19 globally.

Ventilators are needed because the virus attacks the lungs. The patients with serves symptoms often need ventilators to breathe. New York's Governor Andrew Cuomo said the state needed 30,000 ventilators to prepare for the apex of the outbreak.

Mr Musk purchased 1,255 ventilators from three manufacturers - ResMed, Philips and Medtronic - last week. He said his company would be giving all its ventilators away "whether we buy them or build them".

Earlier this month, Mr Musk pledged to reopen Tesla's gigafactory in Buffalo, New York - which builds solar cells - and repurpose it to manufacture additional ventilators.

"Giga New York will reopen for ventilator production as soon as humanly possible. We will do anything in our power to help the citizens of New York," he wrote on Twitter.

The company had suspended production at its factories in New York and California.

These donations appear to mark a turn in Mr Musk's view of the coronavirus. In early March he tweeted that the panic over coronavirus was "dumb". In another tweet he suggested children were "essentially immune" to the virus - which is false.

Tesla is not the only US carmaker offering to produce ventilators and other needed hospital supplies.

Ford and General Motors are also intending to do so. But those arrangements hit a snag on Friday after US President Donald Trump accused the companies of overcharging for the machines.