American authorities warned a spike in virus deaths was coming after millions of Americans traveled for the Thanksgiving holiday last month, ignoring pleas to stay home to slow the spread of the virus.
At least 3,253 American patients died on Wednesday alone, according to a Reuters tally of state-by-state data.
The figure surpassed the previous Dec. 3 record of 2,861 COVID deaths and marked the first time the virus has claimed 3,000 American lives or more in a single day - exceeding the death toll from the September 11, 2001 terrorist attacks on America.
California, where some 33 million people were back under lockdown this week, saw more than 30,000 COVID cases on Wednesday, the highest 24-hour tally in a US state, according to the COVID Tracking Project.
Ten mostly rural counties across California reported having no ICU beds on Wednesday, according to state health figures.
The number of COVID patients hospitalized in the US grew to a new all-time high of 106,217 by late Wednesday, up some 18% over the previous two weeks.
Some 15 million people have contracted COVID-19 in the US since the start of the pandemic.
The record-breaking virus deaths in the US come as American public health officials stepped up preparations for a vaccine campaign ahead of final regulatory review.
US experts are due to meet on Thursday to examine whether a vaccine from Pfizer Inc and German partner BioNTech SE. should receive emergency authorization in the coming days.
Emergency use authorization of the US Food and Drug Administration could come as early as Friday or Saturday, followed by the first US injections on Sunday or Monday, Moncef Slaoui, chief adviser to the Trump administration’s Operation Warp Speed vaccine development program said.
US medical experts expect yet another surge of virus infections and hospitalizations as Americans have refused to follow guidance for wearing face coverings and disregarded warnings to avoid unnecessary travel and large gatherings over the year-end holidays.