New coronavirus cases shot up by more than 50,000 on Wednesday. marking the biggest one-day spike since the start of the pandemic.

An empty outdoor seating area on July 1, 2020 in El Paso, Texas.
An empty outdoor seating area on July 1, 2020 in El Paso, Texas. (AFP)

Governors of US states hit hardest by the resurgent coronavirus have halted or reversed steps to reopen their economies. The move on is being led by California, the nation's most populous state and a new epicentre of the pandemic.

New cases of Covid-19, the illness caused by the coronavirus, shot up more than 50,000 on Wednesday, according to a Reuters tally, marking the biggest one-day spike since the start of the pandemic.

"The spread of this virus continues at a rate that is particularly concerning," California Governor Gavin Newsom, a Democrat, said, ordering the closure of bars, bans on indoor dining and other restrictions in 19 counties, affecting over 70 percent of the state's population.

The change in California, which was the first US state to impose sweeping stay-at-home restrictions in March, will likely inflict more financial pain on the owners of bars and restaurants who have struggled to survive the pandemic.

Epicentre shift 

The epicentre of the country's Covid-19 epidemic has moved from the Northeast to California, Arizona and New Mexico in the West, along with Texas, Florida and Georgia.

Texas again topped its previous record on Wednesday with 8,076 new cases, while South Carolina reported 24 more coronavirus deaths, a single-day high for the state. Tennessee and Alaska also had record numbers of new cases on Wednesday.

The US recorded its biggest one-day increase of nearly 48,000 new infections on Tuesday, including more than 8,000 each in California and Texas, a Reuters tally showed.

New Mexico Governor Michelle Grisham, a Democrat, on Wednesday extended the state's emergency public health order through July 15, saying 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," Grisham said. "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."

READ MORE: US states backtrack on Covid-19 measures as new cases reach record high

'Virus on the prowl'

In Indiana, Republican Governor Eric Holcomb halted his state's phased reopening until at least mid-July.

"We just have to accept the fact ... that again this virus is on the prowl and it is moving, and it's moving even within our borders,” he said.

New York Mayor Bill de Blasio, a Democrat whose city was for months at the centre of the US outbreak, said on Wednesday he would postpone a plan to allow indoor restaurant dining beginning Monday.

“We see a lot of problems and we particularly see problems revolving around people going back to bars and restaurants indoors, and indoors is the problem more and more,” de Blasio told reporters.

Americans concerned

A Reuters/Ipsos poll found Americans are increasingly worried about the spread of Covid-19, the serious and sometimes fatal illness caused by the coronavirus.

Roughly seven in 10 Republicans said they were personally concerned about the virus's spread, up from six in 10 in previous polls. About nine in 10 Democrats said they are similarly worried, a level of concern that has not changed.

Conservatives have generally been less willing to wear masks or follow other restrictions imposed by local authorities to stop the spread of the virus as the issue has become increasingly politicised.

US President Donald Trump, who has been reluctant to don a mask himself, told the Fox Business Network on Wednesday that he used face coverings when in close quarters with other people but did not think mask-wearing needed to be mandatory.

Source: Reuters