GENEVA/BRUSSELS (Reuters) – Leaders of 23 countries and the World Health Organization on Tuesday backed an idea to create an international treaty that would help deal with future health emergencies like the coronavirus pandemic by tightening rules on sharing information.

The idea of such a treaty, also aimed at ensuring universal and equitable access to vaccines, medicines and diagnostics for pandemics, was floated by the chairman of European Union leaders, Charles Michel, at a summit of the Group of 20 major economic powers last November.

WHO Director-General Tedros Adhanom Ghebreyesus has endorsed the proposal, but formal negotiations have not begun, diplomats say.

Tedros told a news conference on Tuesday that a treaty would tackle gaps exposed by the COVID-19 pandemic. A draft resolution on negotiations could be presented to the WHO’s 194 member states at their annual ministerial meeting in May, he said.

The WHO has been criticized for its handling of the COVID-19 pandemic and was accused by the administration of U.S. president Donald Trump of helping China shield the extent of its outbreak, which the agency denies.

A joint WHO-China study on the virus’s origins, seen by Reuters on Monday, said it had probably been transmitted from bats to humans through another animal, and that a lab leak was “extremely unlikely” as a cause. But the study left many questions unanswered and called for further research.

On Tuesday, the treaty proposal got the formal backing of the leaders of Fiji, Portugal, Romania, Britain, Rwanda, Kenya, France, Germany, Greece, Korea, Chile, Costa Rica, Albania, South Africa, Trinidad and Tobago, the Netherlands, Tunisia, Senegal, Spain, Norway, Serbia, Indonesia, Ukraine and the WHO itself.

“There will be other pandemics and other major health emergencies. No single government or multilateral agency can address this threat alone,” the leaders wrote in a joint opinion piece in major newspapers.

“We believe that nations should work together towards a new international treaty for pandemic preparedness and response.”

The leaders of China and the United States did not sign the letter, but Tedros said both powers had reacted positively to the proposal, and all states would be represented in talks.

The treaty would complement the WHO’s International Health Regulations, in force since 2005, through cooperation in controlling supply chains, sharing virus samples and research and development, WHO assistant director Jaouad Mahjour said.

(Reporting by Jan Strupczewski and Philip Blenkinsop in Brussels and Stephanie Nebehay in Geneva; Editing by Kevin Liffey)