Hyundai is thinking about building its fourth assembly plant in China.

Although Hyundai announced last week that it won't build an additional assembly plant in the United States, the automaker's vice chairman says that a fourth assembly plant is possible for China.

"We expect our capacity in China to become constrained by 2015 and 2016... and are considering a plant with a capacity of 300,000 [new cars]," Hyundai Motor Vice Chairman Hsueh Yung-hsing told Reuters.

The automaker is considering western China for the new plant. It's not clear what vehicles Hyundai will build in China, the world's largest new car market. Although Hyundai's sales have leveled off in North America after years of unprecedented growth, the brand continues to expand in China. In part, that strength is due to weak demand for Japanese-branded cars in China after a territory rift between the two Asian countries drove Chinese consumers away from products from Japan.

By contrast, Hyundai (including its Kia division) has just two assembly plants in the United States.