As respiratory viruses strain US health care systems, Biden administration tells states how it's ready to help

Nearly 20,000 people in the United States were admitted to the hospital for flu last week, almost double the number of admissions from the week before, according to data updated Friday by the US Centers for Disease Control and Prevention.

The CDC estimates that there have been at least 8.7 million illnesses, 78,000 hospitalizations and 4,500 deaths from influenza this season.

In a letter to the nation's governors Friday, US Health and Human Services Secretary Xavier Becerra notes that flu and other respiratory viruses are "increasing strain" on the country's health care systems.

In a letter obtained exclusively by CNN, Becerra wrote that the Biden administration "stands ready to continue assisting you with resources, supplies, and personnel."