With winter closing in and COVID-19 cases on the rise, hospitals across the United States are once again facing the pressures of caring for thousands of patients.

More than 67,000 people are currently hospitalized with COVID-19 nationwide, according to federal data.

Rebecca Long, lead nurse in a COVID-19 intensive care unit at Nebraska Medical Center in Omaha, told ABC News that she and her team "literally do not have any ICU beds" available.

"I don't want anyone else's family member or loved one to have to be in the position where we say, like, we can't help you because we don't have the resources," Long said. "As health care providers, all we want to do is help people and we can't because we physically can't."

Dr. Kyle McCarty, medical director of emergency services at both HSHS St. Mary's and HSHS St. Vincent hospitals in Green Bay, Wisconsin, told ABC News that health care workers are feeling burned out after "being asked to do more with less."

"We're exhausted by the knowledge that we are the duct tape that is preventing a complete collapse of the health care system," McCarty said. "There's a national shortage of hospital staff, which is making it difficult to take care of patients the way that we want it. There aren't enough inpatient beds for the patients that need to be admitted to the hospital."

"This is a call for reinforcements, not a warning to stay away, because we don't want this to be the new normal," he added. "If we can recruit more health care teammates, it doesn't have to be."

-ABC News' Arielle Mitropoulos

The number of people who have died from COVID-19 in the United States surpassed 800,000 on Tuesday, according to real-time data compiled by Johns Hopkins University's Center for Systems Science and Engineering.

The figure is greater than the approximately 700,000 Americans who have died from AIDS-related illnesses over the last four decades, and it's higher than the total number of U.S. troops who have fallen in battle since 1900.

Since last December, when the first COVID-19 vaccines were being administered, an additional 500,000 people in the U.S. have died from the virus.

Of those, some 230,000 have died since April 2021, when U.S. President Joe Biden announced COVID-19 vaccines were widely available to every American over the age of 18.

-ABC News' Arielle Mitropoulos

The U.S. saw a sevenfold increase in the prevalence of the omicron COVID-19 variant over the last week, according to data from the U.S. Centers for Disease Control and Prevention.

Just over two weeks after it was first discovered in the country, the omicron variant is now estimated to account for nearly 3% of all new cases in the U.S., the latest data from the CDC shows.

Last week, omicron accounted for an estimated 0.4% of all new cases, according to the data.

-ABC News' Arielle Mitropoulos

Dr. Anthony Fauci told CNN Tuesday that omicron will "for sure" become the dominant strain in the U.S. given how rapidly it is spreading.

"Omicron is going to be a challenge because it spreads very rapidly," Fauci said.

Fauci reiterated that omicron so far appears to be less severe, adding, "Whether it is inherently less pathogenic as a virus or whether there is more protection in the community, we're just going to have to see when it comes in the United States."

-ABC News' Arielle Mitropoulos

Dr. Anthony Fauci, the nation's leading expert on infectious diseases, warned Thursday that omicron will become the dominant variant of the novel coronavirus in the United States "very soon."

"It has an extraordinary ability to transmit efficiently and spread," Fauci, the chief medical advisor to U.S. President Joe Biden, told ABC News' George Stephanopoulos in an interview on "Good Morning America."

"It has what we call a doubling time of about three days and if you do the math on that, if you have just a couple of percentage of the isolates being omicron, very soon it's going to be the dominant variant," he explained. "We've seen that in South Africa, we're seeing it in the U.K. and I'm absolutely certain that's what we're going to be seeing here relatively soon."

Fauci, who is also the director of the National Institute of Allergy and Infectious Diseases, urged Americans to "absolutely" get vaccinated against COVID-19, if they haven't already, and to also receive a booster shot when they become eligible.

"At this point, we don't believe you need an omicron-specific boost," he added. "We just need to get the boost with what you got originally for the primary vaccination."