A staggering 10 million US workers have lost their jobs in the second half of March as the coronavirus forced stores and businesses nationwide to close their doors.

The data have left analysts at a loss for words as they try to gauge the damage, while politicians and economists blame policymakers and President Donald Trump for failing to prepare the country for the unprecedented economic hit.

Another 6.65 million US workers filed for unemployment benefits for the first time last week, the most ever recorded, the Labor Department reported Thursday.

The number for the week ended March 28 was double the amount registered in the previous week, which was revised up by 24,000 to 3.3 million - the previous record, according to the data.

"Nearly every state providing comments cited the Covid-19 virus," the report said, noting a widening impact across industries, especially hotels, but also manufacturing and retail.

The result far surpassed even the highest of estimates by economists, and reflected the growing damage to the US economy as the pandemic worsens and the rising death toll prompts more states to impose lockdowns.

Bustling cities have been turned into ghost towns, as Covid-19 restrictions have forced shops, restaurants and offices to close, leaving grocery stores and hospitals the lone epicenters of activity.

Trump, after playing down the threat for weeks, has begun to prepare Americans for worse news to come.

"We're going to have a couple of weeks... that are going to be horrific," Trump said late on Wednesday at his daily White House briefing on the pandemic.

Some economists are predicting the worst job losses since World War II, with the country already in a severe recession.

In the same week of last year, only 211,000 people requested unemployment benefits for the first time.

'No words'

Even analysts who had expected grim figures were stunned.

"No words for this," said Ian Shepherdson of Pantheon Macroeconomics.

"We're hoping today's reading will be the peak, but we can't be sure," he said in an analysis. "In any event, total layoffs between the March and April payroll surveys look destined to reach perhaps 16 to 20 million, consistent with the unemployment rate leaping to 13 to 16%. In one month."

The government last week approved a $2.2 trillion rescue package that includes a massive expansion and extension of unemployment benefits to cushion the blow for the millions of workers left without a paycheck.

The program also includes $349 billion in loans to businesses that will be forgiven if they are primarily used to pay workers, even those already dismissed.

But even so, analysts warn the record-low US unemployment rate is likely to surge into double-digits as early as April.

More stimulus coming?

Former vice president Joe Biden, the Democratic frontrunner in the November presidential election, blamed Trump for delaying the response.

"Donald Trump is not responsible for the coronavirus, but he is responsible for failing to prepare our nation," Biden said in a statement, lambasting "the erratic and unacceptably slow federal response that has tragically lagged behind other countries."

Shepherdson likewise lamented the government response, and said another stimulus package is "inevitable."

"It didn't have to be this way; the US could have followed the lead of several major European countries and offered job retention programs," he said. "The result will be even greater dislocation for both people and businesses, some of which could have been avoided."

The official employment report for March due out Friday will not show the full extent of the job losses because of the nature of how that report is compiled, looking at payroll data in the week including the 12th day of the month - which in March was before the most stringent lockdowns took effect.