North Korean firms in China ordered to close by January under UN sanctions

China has ordered North Korean companies in the country to shut down by January as it applies UN sanctions imposed following Pyongyang's sixth nuclear test, the commerce ministry said today.

The ministry said the companies, including joint ventures with Chinese firms, have 120 days to close from the date the United Nations resolution was adopted, September 11.

The announcement comes days after China confirmed that it will apply another major part of the sanctions: a limit on exports of refined petroleum products to North Korea starting October 1 and a ban on textiles from its neighbour.

China's application of UN sanctions is particularly biting for North Korea. Beijing is Pyongyang's main ally and trading partner, responsible for around 90 per cent of the hermit nation's commerce.

The US has pressed China to use its economic leverage to strongarm North Korea into giving up its nuclear ambitions.

US Secretary of State Rex Tillerson will visit Beijing this weekend for talks with China's top diplomat, Yang Jiechi, and Foreign Minister Wang Yi.