North Korean leader Kim Jong-il has arrived in China, his destitute state’s biggest benefactor, for a rare trip abroad that could defuse regional tensions and bring him much-needed aid, reports said on Monday.

China has the most influence in curbing the North’s military grandstanding and the reclusive Kim’s previous trips to his neighbour have led to steps that have reduced security concerns for the economically vibrant region and between the rival Koreas.

The trip to China would be the first in four years and comes at a time when South Korea is considering ways to respond to a suspected North Korean attack on one of its naval ships. South Korea lost 46 sailors in what could be one of the deadliest strikes since the end of the 1950-53 Korean War.

“We have confirmed the arrival of a special train at (the Chinese border city) Dandong, and we believe it is highly likely that Chairman Kim is on board,” a South Korean government official told Yonhap news agency.

Kim later entered the Chinese port city of Dalian, Yonhap quoted officials as saying. In his last trip in 2006, Kim toured China’s industrial centres for a first-hand look under the hood of the country’s quickly growing economy.

Dalian, a thriving city that has attracted major foreign investment, is a symbol of development that Beijing’s leaders have advocated for years to Kim and his father and state founder Kim Il-sung to revive the North’s moribund economy.

A booking agent at the Furama Hotel in the city where Kim is thought to be staying told Reuters it was not accepting reservations for Monday because of “an event”.

There has been no confirmation of the trip, and reporters, camping out along the railway line that Kim’s special armoured train would have to use to enter China, were hounded out of the area by Chinese security agents just before the suspected crossing.

Yonhap said the train thought to have carried Kim crossed in the pre-dawn hours of Monday with several hundred Chinese security agents sealing off the area around the train station.

Witnesses at the border said the security clampdown ended a few hours afterwards. The North’s KCNA news agency’s last report on Kim was on Saturday and said he attended a May Day concert in Pyongyang where songs including “This Is Icon of Socialism” and “Where Are You, Dear General” were performed.

In another sign pointing to a visit, a North Korean performance troupe that played at a meeting between Kim and top Chinese officials in Pyongyang, has entered China for shows in Beijing, a major Chinese newspaper reported.

The visit would be Kim’s first trip abroad since a suspected stroke in 2008.

PUNISHING PYONGYANG

South Korea is expected to seek economic and political punishment against Pyongyang for the attack on the ship but avoid a revenge strike that might spark an escalating conflict between the rivals and devastate its own quickly recovering economy.

China, fearful of a collapse of the Kim family regime that would bring chaos to its border, has supported the North’s leaders for decades.

It wants to prevent an escalation of military tension but is unlikely to punish its neighbour if it was to blame for the attack on the warship, analysts said.

Kim is even more reliant on China’s help after a botched currency reform at the end of last year worsened inflation and sparked rare civil unrest that raised questions about Kim’s grip on power in the state his family has run for more than 60 years.

“China has heard from South Korean President Lee Myung-bak on the ship sinking when he met President Hu Jintao last week and now it could hear from North Korea,” said Yang Moo-jin, a professor at the South’s University of North Korean Studies.

Yang said Beijing will weigh its options and see how far it is willing to cooperate with Pyongyang.

Analysts said Kim may be heading to China to seek financial aid in exchange for a return to international nuclear disarmament-for-aid talks hosted by Beijing that Pyongyang has boycotted for over a year.

Kim’s trip to China in 2000 was soon followed by a summit in Pyongyang with South Korea’s leader and the start of two major joint development projects in North Korea. A China trip in 2004 led to a push for talks on the North’s nuclear programmes.

The North has come under pressure to return to six-country nuclear talks due to U.N. sanctions imposed after a May 2009 atomic test that have dealt a blow to its wobbly economy.

The North’s official media did not announce his 2006 visit until after Kim’s armoured train crossed the border and he was safely back in North Korea.

(Writing by Jon Herskovitz in Seoul; Additional reporting by Chris Buckley in Beijing and Christine Kim and Cheon Jong-woo in Seoul; Editing by Jonathan Thatcher and Sanjeev Miglani)