The Mongolian Transport Department has been issuing ‘C’ category international transport documents to enterprises which operate under the country’s laws. Under Mongolian regulation, the enterprises must have professional drivers and pay their social and health insurance. However, companies with Chinese investment  complained about paying health insurance for drivers. Subsequently, China has closed entry to Mongolia at the Gashuun Sukhait border crossing for two days. According to officials, the two countries are trying to solve this issue.