The US is pulling out of the UN’s cultural organisation Unesco, accusing it of “anti-Israel” bias.
The agency is known for designating world heritage sites such as Syria’s Palmyra and the US Grand Canyon.
The state department said it was also concerned about mounting financial arrears at Unesco and said the agency needed to be reformed.
Unesco head Irina Bokova said the withdrawal was a matter of “profound regret”.
The withdrawal represented a loss to the “UN family” and to multilateralism, Ms Bokova added.
The US will establish an observer mission at the Paris-based organisation to replace its representation, the state department said.
The decision follows a string of Unesco decisions that have drawn criticism from the US and Israel.
In 2011 the US cancelled its budget contribution to the agency in protest at its decision to grant full membership to the Palestinians.
And last year, Israel suspended cooperation with Unesco after the agency adopted a controversial resolution which made no reference to Jewish ties to a key holy site in Jerusalem.
Then earlier this year, the Israeli Prime Minister Benjamin Netanyahu condemned Unesco for declaring the Old City of Hebron in the West Bank a World Heritage site.
The US withdrawal is also motivated by a desire to save money, Foreign Policy magazine reported.
US President Donald Trump has criticised what he sees as a disproportionate contribution by the US to UN institutions. The US funds 22% of the UN’s regular budget and 28% of UN peacekeeping.
Unesco is in the process of choosing a new leader, with Qatari and French former ministers Hamad bin Abdulaziz al-Kawari and Audrey Azoulay neck-and-neck in the contest to replace Ms Bokova.