SACRAMENTO, CALIFORNIA (REUTERS) - California's governor said on Monday (Nov 30) the state was at a "tipping point" in the Covid-19 pandemic that would soon overwhelm hospitals as political leaders nationwide turn to increasingly aggressive measures to hold back the latest surge.

Governor Gavin Newsom said he may clamp new "stay-at-home" orders on California's roughly 40 million residents in the face of infections and hospitalisations that are still rising weeks before emergency vaccines are predicted for release.

"(California) has worked hard to prepare for a surge - but we can't sustain the record high cases we're seeing," Mr Newsom said on Twitter. "Current projections show CA will run out of current ICU beds before Christmas Eve."

The governor told reporters discussions were underway among state health officials over the potential stay-at-home order. He expects to issue a decision in the next day or two.

Last week, Mr Newsom instituted a curfew barring social gatherings and other non-essential activities across most of the state between 10pm and 5am daily.

The curfew and other constraints placed on social and economic activity across California, already represent some of the most stringent Covid-19 public health measures in effect nationwide.

More than 4.2 million new Covid-19 infections and 36,000 Covid-19 related deaths were reported across the United States in November, according to a Reuters tally.

Hospitalisations are at a pandemic high and deaths the most in six months.

Nearly 93,000 Americans are currently hospitalised with Covid-19, up 11 per cent from last week and double the number reported a month ago, according to a Reuters analysis of state and county public health reports.

California's top health official, Dr Mark Ghaly, said they are primarily focused on trying to curb soaring Covid-19 infection rates that are expected to strain hospital resources to a dangerous level.

Roughly 12 per cent of daily new Covid-19 cases in California end up requiring hospitalisation within two weeks of infection, with as many as 30 per cent of patients eventually requiring admission to ICU wards or respiratory support, they said.

Coronavirus-related hospitalisations have already climbed nearly 90 per cent over the past two weeks, Mr Newsom said.

Even more alarming, the governor cited data projections showing hospital ICU wards reaching 112 per cent of capacity by mid-December statewide - and 134 per cent of capacity in northern California by early next month - even if hospitals overall have room to spare.

Three-fourths of ICU beds statewide are already occupied.

"What we worry about this time is specifically the ICUs," Dr Ghaly said. "Even when we may be using only 70 per cent of our hospital beds in the state, we're using over 100 per cent of the projected capacity in ICU space."

Americans who have endured eight months of restrictions, lockdown and business closures in the face of the pandemic are pinning their hopes on vaccines developed by drug companies Pfizer Inc and Moderna that are awaiting US government approval for emergency use.

US Health Secretary Alex Azar said Pfizer's medication could be authorized and shipped within days of a Dec 10 meeting of outside advisers to the Food and Drug Administration.

Moderna's vaccine could follow a week later, Mr Azar said, after the company announced on Monday it would apply for emergency authorization both in the US and Europe.

"So we could be seeing both of these vaccines out and getting into people's arms before Christmas," Mr Azar said on CBS' "This Morning."

Health officials in many states say that even after the vaccines are approved the rollout to Americans nationwide could be slowed by shortages of personal protective equipment and other factors.

The non-partisan Government Accountability Office reported on Monday that some diagnostic test kits and accompanying reagents, as well as PPE are hard to come by "due to a supply chain with limited domestic production and high global demand."

In Los Angeles, health officials on Friday banned all public and private gatherings for at least three weeks and urged residents to stay home as much as possible.

In New York, Governor Andrew Cuomo on Monday ordered all elective surgeries to cease in one county and told hospitals statewide to plan on increasing their capacity by 50 per cent if necessary or set up and staff field hospitals.

"Hospital capacity is the top concern," Mr Cuomo said.

New Jersey Governor Phil Murphy said that as of Saturday he was re-tightening the limit on most outdoor gatherings to 25 people.

Mr Murphy, who has brought back a series of Covid-19 restrictions in recent weeks, also said all indoor youth and adult sports will be put on hold from Dec 5 through Jan 2, 2021, also with exemptions.