The reclusive Kim was due to board a train for the 15-hour journey back to Pyongyang after spending the morning at a "model village" in Beijing's southwest, South Korea's Yonhap news agency said, citing sources.

Kim was advised to visit the village, which used to be poor but now is one of the richest towns in China, by Chinese officials as he desperately seeks ideas on how North Korea's struggling economy can imitate China's vibrant growth.

Yonhap said around 10 journalists were detained by Chinese police as they attemped to cover the village tour in Fangshan district, highlighting the sensitive nature of Kim's visit.

Heavy security has surrounded him since his arrival Monday on a trip which has not been announced officially by China or North Korea.

It is Kim's first time in China since a new leadership was installed in Beijing in March 2003.

According to observers, the economic reforms Kim introduced in recent years have failed and the Stalinist state is struggling to cope with food and energy aid from the international community in short supply.

Finding a solution to the nuclear issue is seen as the key to unlocking outside aid, but few signs have emerged from Kim's visit that an end to Pyongyang's 18-month standoff with the United States is in sight.

While Chinese President Hu Jintao reportedly told Kim to soften his hardline stance toward the United States, the North Korean leader reiterated that Washington must first offer compensation before he freezes his nuclear facilities.

Reports also said that Kim, rarely seen in public, was dubious about US security guarantees and expressed concern over a possible attack by the United States.

Hu told him that Washington was highly unlikely to launch military strikes, South Korean newspapers reported.

The United States has repeatedly insisted on a "complete, verifiable and irreversible" dismantling of Pyongyang's nuclear facilities, while Pyongyang wants security guarantees and a resumption of aid first.

China has been under pressure to prod Kim in the right direction after US Vice President Dick Cheney warned during a visit to China last week that time was running out to resolve the standoff.

China has been hosting six-nation talks to end the crisis, which also brings together South Korea, Russia and Japan.

A new round of talks is scheduled to take place before the end of June and China Tuesday expressed confidence that they would go ahead as planned.

Yonhap said Kim exchanged goodbyes with Hu Tuesday night at a farewell party hosted at Zhongnanhai, the residence of China's top leaders in Beijing. He has also met with military chief Jiang Zemin and Premier Wen Jiabao.

Kim is expected to board his train near the "model village", and may break off the return journey at the northeastern Chinese city of Shenyang to visit a computer software company that has been set up there by North Koreans, the agency added.

WAR.WIRE