North Korean leader Kim Jong-il has visited the Chinese port city of Tianjin.

Arriving in the city by special train on Wednesday, Kim visited and toured the Binhai New Area, a special economic zone in the city, around 8 a.m.

Kim seems to have visited the area in order to collect related information for the North's plan to develop its ports of Rajin and Seonbong. It is Kim's second visit to the zone since April 2004.

The Binhai New Area, 30 minutes from Beijing by high-speed train, houses manufacturing, logistics, finance and high-tech industries as well as some 100 South Korean companies. The area is emerging as a key economic center in the Chinese region that includes Beijing, Hebei, Shandong and Liaoning.

A train thought to be carrying the North Korean leader left Tianjin later in the day for Beijing. However, it has yet to be confirmed whether Kim was indeed on board.

Sources in Beijing say Kim is likely to hold a summit with Chinese President Hu Jintao on Thursday.