If the U.S. withdraws funding and support from WHO, critical programs that support the survival of women and children will be at risk.

WHO’s constitution, drafted in New York, doesn’t have a clear exit method for member states. A joint resolution by Congress in 1948 outlined that the U.S. can withdraw with one year's notice. This is contingent, however, on ensuring that its financial obligations to WHO “shall be met in full for the organization’s current fiscal year.”

In this April 15, 2020 file photo, the logo and building of the World Health Organization (WHO) headquarters in Geneva, Switzerland.

Tania Cernuschi, a WHO staff member of 10 years who has worked on improving vaccine access, said she thought of the campaign when she could not sleep after Trump's announcement.

By withdrawing from the World Health Organization and overhauling aid, Trump's new executive orders endanger Americans and the globe, researchers warn. The move also cedes U.S. power to other nations.

The World Health Organization is drawing up a list of reasons why the U.S. should remain in the WHO for its own good, two sources familiar with the process told Reuters, as part of an attempt by its supporters to lobby incoming President Donald Trump.

Public health experts say the United States’ departure could cripple the WHO’s operations or leave an opening for China to assume greater control over the agency.

By Patrick Wingrove, Jennifer Rigby and Emma Farge NEW YORK/GENEVA (Reuters) - The United States will leave the World Health Organization, President Donald Trump said on Monday, saying the global health agency had mishandled the COVID-19 pandemic and other international health crises.

The World Health Organization said Friday it was reviewing its priorities ahead of the withdrawal of its largest donor the United States, noting the agency provides vital services to protect against health threats.

A health organization created in the wake of World War II to fight disease across the planet is losing its biggest donor, the United States.

GENEVA/LONDON -- The World Health Organization will cut costs and review which health programmes to prioritise after President Donald Trump announced he was withdrawing the U.S. from the WHO, the agency's chief told staff in an internal memo seen by Reuters.