China defended its overseas Confucius Institute programs on Friday after new questions were raised in the United States about their transparency and effect on academic freedom.

Confucius Institutes around the world are established by universities voluntarily, China said, and such centers promote Chinese-language learning and academic and cultural exchanges.

On Thursday, the US House Committee on Foreign Affairs held a hearing into whether academic freedom is threatened by China's influence on US universities, with the Confucius Institute receiving particular attention.