The World Health Organization has announced that Ellen Johnson Sirleaf, Liberia’s former president, and Helen Clark, New Zealand’s former prime minister, are to head a panel to review the global response to the Covid-19 pandemic.

Johnson Sirleaf and Clark will head the newly formed Independent Panel for Pandemic Preparedness and Response. The announcement follows the Trump administration’s formal notification to the U.N. of its withdrawal from WHO, which won’t take effect until July 6, 2021 with a possibility of reversal by a new administration or changed circumstances.

Sirleaf led Liberia during the Ebola epidemic that began in 2014, when more than 11,000 people were infected with the virus and died. New Zealand has been lauded as a success story for its handling of the coronavirus pandemic. There have been no locally-acquired cases reported there since May 22.

The World Health body’s chief, Dr. Tedros Adhanom Ghebreyesus, said it was time to reflect and to strengthen collaboration in order to contain the pandemic.

“Through you, the world will understand the truth of what happened and also the solutions to build our future better as one humanity,” the AFP news agency quoted Tedros as saying. “I cannot Imagine two more strong-minded, independent leaders to help guide us through this critical learning process to help us understand what happened—an honest assessment and to help us understand also what we should do to prevent such a tragedy in the future.”