The US has seen a record rise in the number of daily coronavirus infections after more than 50,000 new cases were reported in a 24-hour period.
Tennessee, Alaska and Texas were among the states that saw their highest daily figure on record, with Texas reporting 8,076 new cases on Wednesday.
South Carolina also reported the highest number of deaths in a single day, with 24 recorded.
The previous daily high of Covid-19 cases was on Tuesday, when 48,000 infections were recorded, but the figure rose to 50,203 on Wednesday, according to a John Hopkins tally.
Restaurants, bars, museums and zoos are being told to close their doors in a move that affects 19 counties representing 72 per cent of the state’s population.
He said: “The spread of this virus continues at a rate that is particularly concerning.”
Governor Newsom added that the restrictions will remain in place for at least three weeks.
Lockdown measures were also enforced in New Mexico as Governor Michelle Grisham extended the state’s emergency public health order until July 15.
She warned that authorities would “aggressively” enforce mandatory mask rules.
“I want to be as clear as I can possibly be: New Mexico, in this moment, still has the power to change the terrible trajectory of this virus,” said Governor Grisham.
“But our time is limited. And we are staring down the barrel of what Texas, Arizona and many other hard-hit states are grappling with.”
The US has the highest coronavirus death toll in the world as more than 128,000 people have died after contracting the disease.
According to the data collected by John Hopkins University, more than 2,685,000 people have been infected with Covid-19 in the US.
States in the country’s Arizona, Texas, Florida and California have halted lockdown easing measures, while some states have ordered residents to wear masks in public.
It comes as President Donald Trump appeared to change his stance of wearing face masks in public.
He told Fox Business: “I’m all for masks. I think masks are good. People have seen me wearing one.”
“If I were in a tight situation with people, I would absolutely.”
His comments came a day after Republican lawmakers suggested that he wear a mask in public to set a good example for Americans.