U.S. COVID-19 case count rose to 15,019,092, with a total of 284,887 deaths, as of 1:26 p.m. local time (1826 GMT), according to the CSSE tally.
California reported the most cases among the states, standing at 1,397,237. Texas registered 1,334,750 cases, followed by Florida with 1,065,785 cases. Illinois recorded 804,174 cases and New York identified 713,129 cases.
Other states with over 400,000 cases include Georgia, Ohio, Wisconsin, Pennsylvania, Michigan, Tennessee and North Carolina, the CSSE data showed.
By far, the United States remains the nation worst hit by the pandemic, with the world's most cases and deaths, making up more than 22 percent of the global caseload.
U.S. COVID-19 cases hit 10 million on Nov. 9, and increased by 5 million within a month.
The past week saw new cases in the United States surge at an alarming speed. U.S. daily cases reached 227,800 on Dec. 4, the highest single-day increase in new cases across the United States since the pandemic began, according to real-time data complied by Johns Hopkins University.
Tuesday also marked the 36th consecutive day that the U.S. daily cases had crossed the threshold of 100,000 since the beginning of November.
Meanwhile, the country also saw a record number of deaths in the past week. A total of 2,879 deaths associated with COVID-19 were confirmed on Dec. 3 in the United States, the largest death toll the country has ever seen in one day since the onset of the pandemic, the CSSE chart showed.
Current hospitalizations soared to an all-time high of 102,148 on Dec. 7, according to The COVID Tracking Project.
Anthony Fauci, U.S. infectious diseases expert, expressed his concern on different occasions on Monday that the full brunt of Thanksgiving travel and gatherings hasn't been felt yet despite record-breaking cases, deaths and hospitalizations the country has already seen.
He urged the public to take serious measures while celebrating the remaining winter holidays, warning that there could be "a surge upon a surge" if more people would rather travel and have gatherings over Christmas.
Without substantial mitigation, the middle of January could be a really "dark time" for Americans, Fauci told New York Governor Andrew Cuomo in an online briefing on Monday.
An updated model forecast by the Institute for Health Metrics and Evaluation at the University of Washington projected a total of 538,893 COVID-19 deaths in the United States by April 1, 2021, based on current projection scenario.