BEIJING North Korea's leader Kim Jong-il reached the Chinese capital under a veil of secrecy on Wednesday, South Korean media said, ahead of talks likely to focus on propping up the North's shaky economy.
China, the North's main benefactor, is also likely to press Kim to return to nuclear disarmament talks that he abandoned last year.
Kim's last visit to China in 2006 brought effusive promises of economic cooperation between the two neighbors, and vows from the North Korean leader to seek progress toward "denuclearization." But both goals have sputtered.
"China continues to confront major policy dilemmas in relations with the North," Jonathan Pollack, an expert on the North Korean nuclear dispute at the U.S. Naval War College on Rhode Island, wrote in a recent study.
"Beijing remains Pyongyang's primary point of diplomatic contact and leading provider of economic assistance, but this has not elicited the results that China anticipated."
Neither China nor North Korea has confirmed Kim is visiting, and there were no definitive sightings in the Chinese capital.
But the green armored train he usually travels in reached Beijing, and an accompanying motorcade entered the walled Diaoyutai State Guesthouse in the city's west. South Korea's Yonhap news agency said Kim was in one of the cars.
Beijing's main Chang'an Avenue was lined with soldiers and lanes heading east toward Tiananmen Square were sealed in the late afternoon while a motorcade escorted by a phalanx of police cars whizzed past, apparently taking Kim to a reception at the Great Hall of the People next to the square.
Kim, 68, gaunt and with a slight limp after a suspected stroke in 2008, has been flanked by tight security after his train crossed into China on Monday and headed to the gleaming coastal city of Dalian.
On Wednesday, Kim visited Tianjin, a port city near Beijing, before his special train and security entourage moved to the Chinese capital.
China's leaders have for decades coaxed Pyongyang to draw lessons from their market reforms, and the tour of the two port cities appears designed to reinforce that message.
North Korea's economy remains shaky, especially after a mismanaged currency redenomination that sent ripples of discontent across the harshly controlled country.
North Korea has been seeking increased investment from China after its economy was dealt new blows by U.N. sanctions for a nuclear test a year ago and a loss of aid from Seoul once worth about 5 percent of the North's GDP.
Kim's trip to China comes at a time of renewed tensions on the Korean peninsula triggered by an attack on a South Korean warship that killed 46 of its sailors. South Korean government officials believe Pyongyang targeted the ship with a torpedo in disputed waters in March.
A South Korean newspaper said Kim should be facing rebuke in Beijing for stoking regional tensions instead of getting a red carpet welcome.
"Aid would end up neutralizing the effects of U.N. sanctions against Pyongyang following its second nuclear test last year and make a joke out of punitive measures the international community could take if the North is responsible for the sinking," the South's biggest daily, Chosun Ilbo, said in an editorial.
(Additional reporting by Lucy Hornby, Alfred Jin and Simon Rabinovitch in Beijing and Cheon Jong-woo in Seoul, Writing by Chris Buckleu in Beijing and Jon Herskovitz in Seoul; Editing by Ken Wills and Jeremy Laurence)