North Korean supreme leader Kim Jong Il's secrecy-shrouded tour of China came to the capital Wednesday for a likely summit with President Hu Jintao as the North appeals for food aid and Beijing presses its communist ally to reform its ailing economy.

China is North Korea's most vital diplomatic and economic supporter and is desperate to prevent a chaotic collapse of Kim's isolated regime, which is again struggling to feed its people following a bitter winter. The trip comes as a U.S. delegation visits North Korea to assess its food needs.

Kim generally avoids foreign travel, but his third trip to China in just over a year shows how much he relies on the neighbor.

China's Foreign Ministry has refused to confirm Kim's presence in China, although South Korea's president said Chinese Premier Wen Jiabao told him that the North Korean leader was there. Wen said Beijing had invited Kim to study, and hopefully adopt, China's market-oriented reforms. The secretive trip reportedly began last Friday.

North Korea has abandoned previous attempts at economic reform and it remains unclear how much 69-year-old Kim — or his anointed successor, son Kim Jong Un — would be willing to change. The communist nation's disastrous attempts at currency reform early last year and the pressure of international nuclear sanctions have put the regime on the defensive, and that might make it less likely to take risks.

South Korean media said Kim arrived in Beijing on Wednesday morning from the southern city of Nanjing aboard his personal train. A motorcade believed to be carrying Kim and his delegation arrived Wednesday evening at the Great Hall of the People, the seat of the legislature in the heart of Beijing where Hu usually receives official visitors.

Kim also visited China last May and August, but the trips were confirmed by Beijing only after he left the country.

In South Korea's capital, Seoul, President Lee Myung-bak cheered Kim's China visits as a positive force for change.

"Visiting there often, watching and learning, and China's assistance — such things would bring about changes," Lee said, according to the Yonhap News agency.

North Korea's exchanges with China have grown even more important since South Korea's conservative government halted unconditional food and fertilizer shipments in early 2008 and suspended almost all trade with the North. The U.N. and other groups also have enacted sanctions to punish the country for violating nuclear agreements.

Kim's trip takes place as an American delegation — led by Robert King, U.S. special envoy for North Korean human rights issues — is visiting North Korea to verify food supply surveys conducted by the United Nations and U.S.-based charities and see if there are ways to monitor aid distribution.

The last U.S. food shipments were stopped in 2009 after nuclear monitors were expelled.

The United Nations said Tuesday it would soon decide whether to release emergency humanitarian funds for the North. The U.N. World Food Program launched a $200 million dollar international appeal late last month after it concluded that more than 6 million of North Korea's 23 million people were in urgent need of aid. It said the North's public distribution system would run out of food between May and July.

Some critics in South Korea and the U.S. say the situation is not so dire, and are concerned that any assistance might be diverted to North Korea's powerful military.


Associated Press writer Foster Klug in Seoul, South Korea contributed to this report.