"I am distressed by the decision to withhold critically needed US funding from the WHO, especially during an international pandemic", Carter said in a statement. "WHO is the only international organisation capable of leading the effort to control the virus".
Trump told reporters on Tuesday he was pulling funding for the WHO while his administration conducted an investigation of the Geneva-based UN agency, claiming it had impeded the US response to the COVID-19 pandemic.
Trump claimed during his White House press conference on Tuesday that the WHO repeated false Chinese claims about the COVID-19 novel coronavirus, such as that it was not communicable, and failed to report accurately on the virus as it emerged in January.
Carter is the oldest living former US president at age 95.