WASHINGTON: President-elect Joe Biden on Monday named the team tasked with turning around the United States' floundering efforts to quell the Covid-19 pandemic, nominating Xavier Becerra as his secretary of health.

When Biden takes office on January 20, his health team will be immediately responsible for rolling out a historic immunization drive - set to launch later this month in a bid to gain control of a pandemic that has killed 280,000 people in the country.

Along with California attorney general Becerra, Biden named Vivek Murthy as surgeon general - a role he previously held under Barack Obama - and Harvard infectious disease expert Rochelle Walensky as director of the Centers for Disease Control and Prevention.

"This trusted and accomplished team of leaders will bring the highest level of integrity, scientific rigor, and crisis-management experience to one of the toughest challenges America has ever faced," Biden said.

Biden, who has said he would ask Americans to wear masks for 100 days when he moves into the White House, vowed his administration would "ready on day one to mobilize every resource of the federal government" to lower the soaring daily death toll from Covid-19.