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 decision follows a string of Unesco decisions that have drawn criticism from the US and Israel.
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.
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....