The public backing for North Korea's 'supreme leader' Kim Jong-un at his father's memorial provides a strong signal that officials have unified around him in the wake of Kim Jong-il's death.
Kim Jong-il's visit to China comes as Jimmy Carter visits Pyongyang to seek the release of an imprisoned American.
North Korea on Tuesday fined and sentenced American missionary Aijalon Gomes to 8 years of hard labor for illegally entering the country. He could become a bargaining chip in six-party nuclear talks.
The move is a response to the UN Security Council statement condemning North Korea's missile launch last week.