He said the US will also resume full funding and staffing support for WHO.
“I am honoured to announce that the United States will remain a member of the World Health Organisation,” Dr Fauci said.
Dr Fauci said the Biden administration “will cease the drawdown of US staff seconded to the WHO” and resume “regular engagement” with WHO.
“The United States also intends to fulfil its financial obligations to the organisation,” he said.
He referred to Tedros Adhanom Ghebreyesus, the WHO director-general, as “my dear friend”.
Other countries and the WHO chief jumped in to welcome the US announcements, and pledged to work with the Biden administration.
“The role of the United States, its role, global role is very, very crucial.”
The United States under Trump had been the highest-profile — and most deep-pocketed — holdout from the COVAX Facility, which has faced financial hurdles and contractual challenges with vaccine manufacturers as well as vast logistical issues.
Both the European Union and China have given their support to the program.