Updated

North Korea has closed its land border with China for trade and visitors and summoned back state workers living on the Chinese side to prepare for the funeral of late leader Kim Jong Il, according to Chinese officials and people in contact with North Koreans.

The blocking of the country's main economic lifeline appears to be a temporary move to allow the government to focus on the funeral on Dec. 28, but it also affords Kim's son and successor, Kim Jong Un, a chance to enforce absolute control over his country's borders and citizens.

Some Chinese businesspeople who work with North Korea said Tuesday they thought the younger Kim could bring reforms. But dissidents in Seoul told reporters the pace of change could be slow, and that the Pyongyang regime is stronger than outsiders presume.

At the main border crossing in Tumen, a Chinese town on the North Korean border that is one of the main transit points for people and goods moving between the two countries, police said the North Koreans had closed their side to all but returning North Koreans shortly after Kim Jong Il's death was announced Monday.

Chinese officials said the same measures had been enforced at other major border crossings in Huichun and Dandong.

More On This...

Many members of the North Korean elite live and work in China -- where the quality of life is far better -- and many others have sneaked over the border, often walking across frozen rivers in winter, to find work in northeastern China.

Click here for more on this story from The Wall Street Journal