Biden announces 500 million more tests will be purchased for Americans.

Officials said the new teams of doctors, nurses and other medical personnel would begin arriving at hospitals in Michigan, New Jersey, New Mexico, New York, Ohio and Rhode Island. They said the teams would help triage patients arriving at hospitals, allowing short-staffed emergency departments to free up space.

The deployments are part of the Biden administration’s efforts to tackle the latest surge of cases caused by the highly contagious Omicron variant. As it has surged, so have new cases, reaching more than 780,000 a day across the country. The number of Americans hospitalized with Covid-19 has hit a record high of about 142,000.

For Mr. Biden, the inability to get control of the pandemic has helped drag down his approval ratings as he enters his second year in office. His aides are intent on publicly communicating their efforts to deal with the virus.

Since Thanksgiving, when Omicron was first discovered in South Africa, the administration has sent over 800 military and emergency personnel to 24 states, tribes and territories, officials said, not counting the personnel Mr. Biden announced on Thursday.

In addition, more than 14,000 National Guard members have been activated in 49 states to help at hospitals with vaccinations, testing and other medical services, officials said. Those deployments have been paid for by the American Rescue Plan, a law that Mr. Biden championed at the beginning of his term.

“To the military medical teams on the ground, thank you for all everything you’re doing,” the president said.

Officials said there would likely be further deployments of military medical personnel in the days ahead as the country continues to struggle with the pandemic.