Israel has said it will join the US in pulling out of the UN’s cultural organisation UNESCO, after US officials cited “anti-Israel bias”.
Israeli Prime Minister Benjamin Netanyahu praised the US decision as “brave and moral”, a statement said.
The agency is known for designating world heritage sites such as Syria’s Palmyra and the US Grand Canyon.
UNESCO head Irina Bokova earlier called the US withdrawal a matter of “profound regret”.
She admitted, however, that “politicisation” had “taken its toll” on the organisation in recent years.
The withdrawal represented a loss to the “UN family” and to multilateralism, Ms Bokova added.
The US withdrawal will become effective at the end of December 2018 – until then, the US will remain a full member. The US will establish an observer mission at the Paris-based organisation to replace its representation, the state department said.
Hours after the US announced its withdrawal, the Israelis joined in, with Prime Minister Netanyahu saying he had instructed his foreign ministry to begin preparations to leave.
As well as accusing UNESCO of bias, the US state department said it was also concerned about mounting financial arrears at the agency and said it should be reformed.
The decision follows a string of UNESCO decisions that have drawn criticism from the US and Israel.
In 2011 the US cut its funding to the agency – slashing its budget by 22% – in protest at its decision to grant full membership to the Palestinians.
And last year, Israel suspended co-operation with Unesco after the agency adopted a controversial resolution which made no reference to Jewish ties to a key holy site in Jerusalem.
The resolution also criticised Israel’s activities at holy places in Jerusalem and the occupied West Bank.
Then earlier this year, Mr Netanyahu condemned Unesco for declaring the Old City of Hebron in the West Bank a Palestinian World Heritage site.
He accused UNESCO of ignoring Judaism’s ancient connection to the city, which includes the crypt where its matriarchs and patriarchs are buried.
The US withdrawal is also motivated by a desire to stop accruing arrears to the agency, Foreign Policy magazine reported. The US cut funding of more than $80m (£60m) of funding to the agency amid the furore over Palestinian membership six years ago, but continues to be charged, and now owes more than $500m, the magazine said.
Mr 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.
The decision to pull out of UNESCO was applauded by the American Israel Public Affairs Committee (Aipac), which said that for years, the agency had “betrayed its original laudatory mission… and chosen instead to unfairly target the Middle East’s lone democracy, Israel”.
The US was a founding member of UNESCO. The Reagan administration withdrew from the organisation in 1984 – accusing the agency of corruption and an ideological bias towards the then Soviet Union – but the US rejoined in 2002.
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.