The United States says it is withdrawing from the United Nations' cultural agency, accusing it of "anti-Israel bias."

State Department spokeswoman Heather Nauert said on October 12 that the United States would form an "observer mission" to take the place of its representation at the UN Scientific and Cultural Organization (UNESCO) effective December 31.

"This decision was not taken lightly, and reflects U.S. concerns with mounting arrears at UNESCO, the need for fundamental reform in the organization, and continuing anti-Israel bias at UNESCO," the State Department said.

UNESCO head Irina Bokova expressed "profound regret" at the U.S. decision, calling it a "loss to multilateralism."

After the U.S. announcement, Israel said it would also withdraw from UNESCO, with Prime Minister Benjamin Netanyahu saying that "instead of preserving history, it distorts it."

Israel has complained about what it says is UNESCO taking sides in disputes over cultural heritage sites in Jerusalem and the Palestinian territories.

Washington stopped funding UNESCO after the agency voted to include Palestine as a member in 2011, but it maintained an office at the UN agency's Paris headquarters.

Among other activities, UNESCO works to protect cultural sites around the world, undertakes efforts to improve education for girls in poor countries and increase awareness of the horrors of the Holocaust, and to defend media freedom.

The United States previously pulled out of UNESCO in the 1980s over complaints that the agency was being used for political reasons. It rejoined in 2003.

Based on reporting by AP, dpa, and AFP