China’s initial timing in alerting the rest of the world to the coronavirus threat appears to be a violation of World Health Organization rules. In 2005, WHO established requirements for member states to report “any event of potential international public health concern” within 24 hours of assessment, and to continue reporting new developments.
WHO rules, like many international treaties, don't outline any processes for claiming compensation or imposing penalties. Former WHO legal consultant David Fidler says it is unlikely other member states would take any action against China, as they wouldn't want to set a precedent that could be used against them. A Finnish researcher notes that a "tacit understanding seems to prevail among states," making the prospect of any action "bleak."