The shift reflects the spread of the omicron variant.
As the COVID-19 pandemic has swept the globe, more than 5.3 million people have died from the disease worldwide, including over 816,000 Americans, according to real-time data compiled by Johns Hopkins University's Center for Systems Science and Engineering.
About 61.7% of the population in the United States is fully vaccinated against COVID-19, according to data from the Centers for Disease Control and Prevention.
Washington, D.C., Mayor Muriel Bowser has declared a state of emergency and is reinstating an indoor mask mandate from Dec. 21 to Jan. 31, 2022.
D.C. is also expanding testing, including offering free at-home rapid tests, the mayor said.
The U.S. is now averaging more than 125,000 new cases each day -- nearly double the average from late-October, according to federal data. In the last two weeks, seven states have seen an increase of 50% or more.
As COVID-19 cases surge, the nation continues to average nearly 1,200 new deaths each day, up by approximately 60% since Thanksgiving, according to federal data.
About one in every 407 Americans has now died from COVID-19.
Daily COVID-19-related hospital admissions have jumped by about 41% in the last month, according to federal data.
-ABC News' Arielle Mitropoulos
The omicron surge will bring "a very challenging few weeks" to New York City, Mayor Bill de Blasio said Monday.
"We are going to see a surge of cases in a few weeks, then we think we will see it trail off," the mayor said.
New York City is adding 23 new city-run testing sites this week to respond to skyrocketing demand, the mayor said. That will bring the number of city-run sites to 112.
-ABC News' Aaron Katersky, Will McDuffie
Tennis star Rafael Nadal tweeted that he tested positive for COVID-19 when he arrived in Spain after playing a tournament in Abu Dhabi.
