"We welcome any and all efforts to strengthen this organisation not for its own sake, but the sake of the people we serve," WHO director-general Tedros Adhanom Ghebreyesus told health ministers at the start of its resumed annual meeting.

U.S. President Donald Trump has accused the WHO of being "China-centric" in its handling of the COVID-19 pandemic, a charge Tedros has repeatedly denied.

Trump has frozen U.S. funding to the WHO and begun a process that would see the United States withdraw from the body next July, drawing wide international criticism amid the pandemic.

Biden has said he would rescind Trump's decision to abandon the WHO on his first day in office.

Tedros urged the international community to recapture a sense of common purpose, adding: "In that spirit we congratulate President-elect Joe Biden and Vice President-elect Kamala Harris and we look forward to working with this administration very closely.

"We need to reimagine leadership, build on mutual trust and mutual accountability to end the pandemic and address the fundamental inequalities that lie at the root of so many of the world's problems," he said.

Tedros was addressing the ministerial session of WHO's 194 member states that resumed on Monday after a short meeting last May. Speaking from quarantine after being in contact with an individual with COVID-19 more than a week ago, he began with a minute's silence, noting that COVID-19 cases approached 50 million with 1.2 million deaths.

An oversight panel called last week for reforms at the WHO including "predictable and flexible" funding and setting up a multi-tiered system to warn countries earlier about disease outbreaks before they escalate.

Tedros said that COVID-19 vaccines being developed should be allocated fairly as "global public goods, not private commodities".