North Korean leader Kim Jong Il returned home from a weeklong trip to China on Friday, saying that ties with Beijing are "sealed in blood" and set to grow for generations to come.
Kim's visit to China, his third in just over a year, was seen by many as an attempt to secure aid, investment and support for his dynastic transfer of power to his youngest son, Kim Jong Un.
North Korea said that Kim Jong Un "warmly greeted" his father Friday at the China-North Korea border.
Kim Jong Il, in a thank-you letter to Chinese President Hu Jintao, said the China-North Korea friendship, "sealed in blood and handed down by the elder generations of the two countries, will develop steadily through generations in the common interests and wishes of the two peoples," according to the North's official Korean Central News Agency.
"During the visit, we realized the invincible vitality of the (North Korea-China) friendship daily growing stronger century after century," Kim said.
North Korea is thought by many to be in dire need of outside help, and China is its only major ally. The North has antagonized many through its pursuit of nuclear weapons and pulled out of international six-nation talks aimed at ridding it of nuclear programs more than two years ago.
Beijing supports a resumption of the negotiations, but South Korea and the United States demand that North Korea first exhibit sincerity toward disarmament.
North Korea's population also faces chronic hunger.
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.
In response to such appeals, 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 by the United nations and U.S.-based charities and see if there are ways to monitor aid distribution.