North Korean leader Kim Jong-il left Beijing on Thursday, a day after a high-profile meeting with Chinese President Hu Jintao on expanding bilateral economic and political relations. Kim\'s special train left Beijing Station at around 2:19 p.m. (local time) and headed north, apparently toward China\'s northeastern region bordering North Korea. The direction of Kim\'s train ride indicated he was on his way back home after concluding a weeklong trip, though Kim could possibly stop over at an unexpected location. In the latest reminder of his interest in computer technology, Kim visited China\'s Silicon Valley, Zhongguancun, with Chinese Vice Premier Li Keqiang before leaving the Chinese capital. Kim\'s train journey, his third in just over a year, culminated in the summit talks with Hu at the Great Hall of the People on Wednesday. The two leaders held in-depth discussions on expanding North-bound food aid, revitalizing economic cooperation and increasing Chinese firms\' investment in the North, among other topics, said sources. No details of the meeting were immediately available as state media of North Korea and China remained silent. The two countries typically reveal details of Kim\'s trips only after he returns home due to security concerns. China plans to debrief South Korea on the results of the summit as early as Thursday evening or Friday morning, diplomatic sources said on condition of anonymity, citing office policy. Kim\'s meeting with Hu, the third in just over a year, illustrates the significance the two neighbors attach to each other, once described as being as close as \"lips and teeth.\" China is the North\'s last remaining ally, key economic benefactor and diplomatic supporter. Meanwhile, North Korea serves as China\'s strategic buffer zone as it keeps at bay 28,500 U.S. troops in South Korea. Kim, who rarely travels abroad, crossed the border into China last Friday at Beijing\'s invitation to study China\'s vibrant economy and seek ways to revive the North\'s faltering economy. China has repeatedly coaxed its impoverished ally to embrace the reform that lifted millions of Chinese out of poverty and helped Beijing\'s rise to becoming the world\'s second-largest economy. The North remains one of the poorest countries in the world, and its economy is unlikely to get better anytime soon as it is under U.N. sanctions over its nuclear tests in 2006 and 2009. Kim visited an automaker, IT companies, a solar energy company and a large discount store as well as a top electronics company as he traveled across China\'s northeastern region and prosperous eastern areas before reaching Beijing. It remains to be seen if Kim\'s trips to economic facilities in China will translate into any specific gestures toward economic reforms. \"Kim will make ostensible efforts toward reforms for the sake of drawing aid and investment from China,\" said Han Ki-bum, a researcher at the state-run Korean Institute for National Reunification. North Korea\'s previous experiments with limited reforms have backfired, deepening the country\'s economic woes with no relief in sight. Kim\'s trip came as his impoverished country is struggling to get food aid and find an exit strategy to break the diplomatic deadlock caused by its two deadly attacks on South Korea last year. North Korea has refused to apologize for the sinking of a South Korean warship, stalling efforts to revive the talks aimed at ending Pyongyang\'s nuclear weapons programs. The two disarmament talks involving the two Koreas, the United States, China, Russia and Japan were last held in 2008.