BEIJING (AP) - North Korean leader Kim Jong Il’s secrecy-shrouded visit to China is aimed at securing economic support for his wrecked economy in exchange for a commitment to return to denuclearization talks, experts and media said Wednesday.

Chinese officials have refused to confirm Kim’s presence in the country, though he has been seen several tims since arriving aboard his armored train on Monday.

China, which sent troops to save the North Korean regime during the 1950-53 Korean War, is widely seen as the country with the most clout with Pyongyang. Kim, who is known to shun air travel, has visited five times since succeeding his father as ruler in 1994, most recently in 2006.

Japanese and South Korean media, which have been closely tracking Kim, reported Wednesday that a train carrying Kim had arrived in the booming eastern port city of Tianjin. His secretive trek by rail and motorcade is expected to eventually bring him to Beijing for talks with state and Communist Party leaders, including President Hu Jintao.

Those discussions are expected to center on further financial help from China, already impoverished North Korea’s biggest source of food and fuel aid and main bulwark against tougher sanctions against Kim’s isolated, hard-line communist regime.