China's southern tropical province of Hainan is adopting a car purchase restriction policy starting May 16, to restrict the increase of cars and promote the use of new-energy vehicles, provincial government authorities said on Tuesday evening.

New car license plates for fuel vehicles will be issued by lottery or auction, and they will be issued for new-energy vehicles by signing up starting on Aug 1, according to the announcement issued by the provincial government of Hainan.

With more than 9 million people, there are more than 1.18 million vehicles in Hainan. The announcement made Hainan the ninth region in the Chinese mainland that has targeted car buyers; other regions include Beijing, Shanghai, Guangzhou, Tianjin, Guiyang, Shenzhen, Hangzhou and Shijiazhuang.

Hainan disclosed a new energy vehicle promotion plan in April during the Boao Forum for Asia 2018 annual conference.

"We are considering island-wide use of new-energy vehicles by 2030," Shen Xiaoming, the governor of Hainan, said at the Boao Forum.

The governor said that the province plans to introduce 5,600 new-energy vehicles into the market and build more than 10,000 recharging posts this year.