Link: https://en.wikipedia.org/wiki/UNESCO

https://en.wikipedia.org/wiki/UNESCO#Israel,_Palestine,_and_the_United_States

October 12, 2017 press statement from the US State Department: https://web.archive.org/web/20190408053146/https://www.state.gov/r/pa/prs/ps/2017/10/274748.htm

October 31, 2011 reporting about the US suspending payment of its dues after Palestine was admitted as a member: https://web.archive.org/web/20200226162636/https://www.reuters.com/article/us-palestinians-unesco-usa-funding/u-s-stops-unesco-funding-over-palestinian-vote-idUSTRE79U5ED20111031

The US is still in UNESCO now since rejoining in July 2023, but plans to officially withdraw again as of December '26. Nerds.

"Also in 2023, the United States stated its intent to rejoin UNESCO, five years after leaving, and to pay its US$600 million of back dues.[65] The United States was readmitted by the UNESCO General Conference that July.[66] Three years later, in 2025, however, the United States stated its intent to withdraw again, to be effective as of December 2026.[67]"

It’s not as if the US has any culture to protect