The US Department of Health and Human Services has mandated its health care workforce to get vaccinated against Covid-19.

Staff at the Indian Health Service, focused on American Indians, and National Institutes of Health will be impacted by this decision, according to an Health and Human Services statement.

Those affected include over 25,000 employees, contractors, trainees, and volunteers whose duties put them in contact or potential contact with patients at an HHS medical or clinical research facility.

"Our number one goal is the health and safety of the American public, including our federal workforce," said Health Secretary Xavier Becerra.

US Public Health Service Commissioned Corps will also be immediately required to get vaccinated, the statement said.

HHS is the latest federal department to make Covid-19 vaccination compulsory.

Earlier this week, the Pentagon said it will seek US President Joe Biden's approval by mid-September to require 1.3 million military members to get vaccinated against Covid-19.

The US Department of Veterans Affairs also announced a similar move last month.

Meanwhile, the Biden administration is examining what authority businesses have to mandate vaccines as it considers what more steps can be done to halt the spread of Covid-19.

United Airlines Chief Executive Scott Kirby said he believes more US companies and organisations will begin requiring Covid-19 vaccinations, after a meeting with Biden on Wednesday.