Areas that were among the first to get hit hard by the Omicron variant are starting to see their Covid-19 numbers level off or even improve. But that's not the case for much of the country, US Surgeon General Dr. Vivek Murthy said.

"There are parts of the country -- New York, in particular, and other parts of the Northeast -- where we are starting to see a plateau, and in some cases, an early decline in cases," Murthy told CNN on Sunday.

"The challenge is that the entire country is not moving at the same pace," he said. "The Omicron wave started later in other parts of the country, so we shouldn't expect a national peak in the next coming days. The next few weeks will be tough."

An average of more than 750,000 new Covid-19 infections were reported every day over the past week, according to Johns Hopkins University data.

That means Americans at work, school and elsewhere face a heightened risk of exposure that is unparalleled during the pandemic.

The number of Americans dying every day from Covid-19 has increased in recent days, with 1,796 Covid-19 deaths reported Sunday, according to JHU data.

And 156,000 people were hospitalized with Covid-19 as of Sunday, according to data from the US Department of Health and Human Services.

The crush of Covid-19 patients means some hospitals are running out of space to treat other patients in intensive care units.

"I expect those numbers to get substantially higher," Dr. Ashish Jha, dean of the Brown University School of Public Health, told Fox News on Sunday.

"The problem is we are running out of health care workforce, we don't have the staffing. So that is going to be a challenge for many weeks ahead."

A nurse tends to a patient in the acute care unit of Harborview Medical Center in Seattle on January 14.