WASHINGTON - The United States has formally withdrawn from the World Health Organisation (WHO).
The move violates US law, which requires Washington to settle more than $260-million in outstanding fees before cutting ties.
Experts also warn the withdrawal could undermine US and global health security.
President Donald Trump signalled his intention to quit the WHO on day one of his second term.
International appeals for a rethink have failed.
The organisation now faces a budget crisis, downsizing staff and slashing programmes after losing what's been its largest single funder.