"This is not the action that a responsible major country should take," foreign ministry spokesman Guo Jiakun said.

"China has always firmly supported the work of UNESCO," he added.

The United States said on Tuesday it would quit UNESCO, best known for establishing world heritage sites, claiming it was biased against Israel and promoted "divisive" causes.

US President Donald Trump also ordered the country's withdrawal from UNESCO in 2017 during his first term. President Joe Biden later reestablished membership.

This latest withdrawal will take effect in December 2026.

Since taking office, Trump has indicated he would pull the United States out of several multilateral institutions -- including the World Health Organization and the Paris climate agreement -- and has launched punishing trade tariffs against allies and foes alike.

China, meanwhile, has sought to promote itself as a responsible major power by expressing support for the United Nations and other international bodies.

"This is already the third time that the US has withdrawn from UNESCO, and it has long been in arrears with its membership fees," Guo told reporters Wednesday.

"We call on all countries to reaffirm their commitment to multilateralism and take concrete actions to support the international system with the UN at its core," he said.