FILE - North Korea's leader Kim Jong Il, right, and Konstantin Pulikovsky, the Russian President's representative in the Far East, center, look at a photo of Larisa Denezhko, left, greeting his father and predecessor, Kim Il Sung, during a visit to the Soviet Union 13 years ago, after he crossed the Russian-North Korean border, south of Vladivostok, on July 26, 2001. North Korea’s Kim Jong Un's train journey to Russia has a storified history. The tradition of train travel extends across the generations. That’s in evidence at the massive Kumsusan Palace of the Sun, where reconstructions of Kim Jong Un’s father’s and grandfather’s train cars, and the leaders’ preserved and displayed remains, are enshrined. (AP Photo/Igor Kochetkov, File)