BEIJING — China will have new standards for gasoline and diesel nationwide in 2017 to cut emissions.

From January, gasoline and diesel must comply with the National V standard, equivalent to the Euro V standard, said regulators on Dec 26.

Sales of substandard fuel will be halted, according to the National Development and Reform Commission website.

China’s major cities have already adopted the National V standard, but in most inland regions, it is not mandatory. Regulators hope a national standard will improve air quality.

Winter smog is commonplace in northern China and vehicle emissions are a major source of the pollution. More than 20 cities issued red alerts for smog this month.

According to the Ministry of Environmental Protection (MEP), China will adopt the tougher “National VI” emission standard by July, 2020.

By the end of 2015, China has more than 170 million vehicles on its roads, including around 150 million light vehicles. Their total missions were estimated at 45.3 million tons in 2015, according to MEP official Liu Bingjiang.