As expected, China has appealed against a recent World Trade Organisation (WTO) ruling that would open the country’s market for US movies, music and books.

China is arguing that its trade barriers are necessary in order to protect public morality. The case will now go before the WTO’s appeals tribunal with a result expected at the end of the year.

The ruling ordered China to stop forcing US content owners to use government-controlled distribution companies. Currently all foreign movies in China are distributed by the state-owned China Film Group Corporation, or a second company, Huaxia Film Distribution, which is part-owned by China Film.

However, it did not address China’s import quotas including an annual quota of 20 revenue-sharing films.

The appeal comes at a time of heightened trade tension between the US and China, ahead of the Group of 20 summit in Pittsburgh this week, and following a decision by the Obama administration to slap punitive tariffs on imports of Chinese tyres.