Roughly half of California’s population could become infected with coronavirus within an eight-week period, Gavin Newsom has warned.

The state governor wrote to Donald Trump asking for resources and detailing the escalation of infections across the region.

“We project that roughly 56 per cent of our population — 25.5 million people — will be infected with the virus over an eight week period,” he wrote.

“In some parts of our state, our case rate is doubling every four days.

“Moreover, we have community-acquired transmission in 23 counties with an increase of 44 community acquired infections in 24 hours.”

Mr Newsom asked Mr Trump to deploy the hospital ship USNS Mercy to Los Angeles to provide relief for healthcare in the badly affected region until 1 September.

“This resource will help decompress the health care delivery system to allow the Los Angeles region to ensure that it has the ability to address critical acute care needs,” the governor wrote.

California has been severely affected by the outbreak of the pandemic, having seen a surge in Covid-19 cases in the last few days with at least 751 people infected with the virus and 13 deaths.

The US has recorded cases of Covid-19 in all 50 states and deaths from the disease in nearly half the states across the country.