Israel and the United States have officially quit the United Nations Educational, Scientific and Cultural Organization (UNESCO), citing “anti-Israel bias.”

The decision, which was announced by the two countries in October 2017, officially took effect at midnight on New Year’s Day.

UNESCO was co-founded by the US after World War II with the mission of seeking to “build peace through international cooperation in Education, the Sciences and Culture.”

Since its establishment, the Paris-based organization has promoted cultural diversity through educational programs in developing countries, and most famously, maintaining a list of World Heritage Sites in efforts to protect unique landmarks across the globe.

The Trump administration has demanded “fundamental reform” from the organization, with the Israeli Ambassador to the UN Danny Danon saying the organization “rewrites history, including by erasing the Jewish connection to Jerusalem.”

“Israel will not be a member of an organization whose goal is to deliberately act against us, and that has become a tool manipulated by Israel’s enemies,” Danon said.

The move is largely being regarded as symbolic, and will not immediately affect the financial situation of the organization, which has been struggling for years since 2011 when both Israel and the US stopped paying dues after Palestine was voted in as a member state.

Leaving UNESCO, by Carlos Latuff.

Israeli officials have long attacked UNESCO for listing several sites in the occupied West Bank and East Jerusalem as “Palestinian World Heritage Sites.”

In 2016, Israeli officials were outraged after UNESCO member states voted in favor of a resolution criticizing the threats posed by the Israeli occupation at the Al-Aqsa Mosque compound in occupied East Jerusalem, criticizing the organization of “erasing” Jewish claims to the city.

In July 2017, Israel’s then Defense Minister Avigdor Lieberman accused UNESCO of being anti-semitic after the organization listed the Old City of Hebron as a World Heritage Site in danger, and the Ibrahimi Mosque, or Tomb of the Patriarchs, as a Palestinian site.

The Old City of Hebron is one of three sites in the occupied West Bank designated as a World Heritage Site in Danger, including Bethlehem Nativity Church, and the sprawling irrigation terraces of Battir village.

Palestinians have long celebrated UNESCO’s recognition of their cultural landmarks, saying that their designation as World Heritage Sites offers a layer of protection for the sites that would otherwise be under threat of destruction or confiscation by the Israeli occupation.