Some fear that a weaker US presence will lead to growing anti-Israeli sentiment within UNESCO, where Arab-led criticism of Israel for territorial reasons has long been an issue.
"We won't be able to have the same clout," said Phyllis Magrab, the Washington-based US National Commissioner for UNESCO. "In effect, we (now won't) have a full tool box. We're missing our hammer."
Israel's ambassador to UNESCO, Nimrod Barkan, told The Associated Press that his country supported the US decision, "objecting to the politicisation of UNESCO, or any international organisation, with the accession of a non-existing country like Palestine."
Elias Sanbar, Palestinian Ambassador to UNESCO told Al Jazeera: "We need them (the United States) to be active. By taking this decision, first of all, they have created big problems for UNESCO, but they have also lost part of their role and we need their role."
UNESCO designates World Heritage sites, promotes global education and supports press freedom among other tasks.