On his first day back in the White House, President Donald Trump initiated the process to withdraw the US from the World Health Organization (WHO), a move previously reversed by President Joe Biden. Scientists warn this could undermine global health efforts against infectious diseases. Trump signed an executive order to pause US funding and reassess partnerships with WHO. The US has historically been a major donor, and withdrawal could severely impact WHO's operations and global health initiatives. Other countries may not fill the funding gap left by the US, and Trump cites corruption and ties to China as reasons for the withdrawal.