He's playing with them. Until he's mulled it over, funding is suspended.
Lurk moar.
https://www.weforum.org/agenda/2020/04/who-funds-world-health-organization-un-coronavirus-pandemic-covid-trump/
And he doesn't want to fund more than other nations, talking about meeting China's funding cap.
https://www.cnbc.com/2020/05/16/trump-administration-reportedly-set-to-restore-partial-funding-to-who.html