On January 7, US president Donald Trump promised to withdraw the US from 35 international organizations and 31 UN agencies:

The Memorandum orders all Executive Departments and Agencies to cease participating in and funding 35 non-United Nations (UN) organizations and 31 UN entities that operate contrary to U.S. national interests, security, economic prosperity, or sovereignty.

Unverified: then the White House deleted the announcement from their website (personal note: I did receive 404 on it for a while).

Correction: announcement is still up or has reappeared. An archived copy is also available in case they change their mind.