Aerial photo taken on May 22, 2020 shows a bulk carrier loading cargoes at a newly built coal berth of Caofeidian Port in Tangshan, north China's Hebei Province. Caofeidian Port's coal berth is a coal discharging project in north China and its construction will be carried out in phases. The first part of the project's Phase Three has been put into use with an expected annual throughput of 50 million tonnes. (Xinhua/Yang Shiyao)

China has been stepping up the quality and safety inspection of imported coal for environmental reasons, Zhao Lijian, a spokesperson of Chinese Foreign Ministry said Wednesday, responding to media reports that Australian coal worth over $500 million was stranded at Chinese ports. 

Chinese customs identified that a large proportion of coal doesn't meet environmental standards in imported coal quality risk analysis and supervision, Zhao said.

He said that China has stepped up quality and environmental inspection on imported coals in line with relevant laws and regulations in order to better protect the legitimate rights and interests of Chinese importers as well as environmental security.

The comment came following Western media reports claiming that Australian coal worth more than $500 million is stranded outside Chinese ports, citing deteriorating ties between the two countries.