Japan's Princess Takamado will arrive in Russia on Monday to watch her national team compete in the soccer World Cup, the Kyodo news agency reported, marking the first visit to Russia by a Japanese royal in over 100 years.
Relations between Moscow and Tokyo are currently strained over the roll-out of a U.S. missile system and Moscow's move this year to deploy warplanes to a group of disputed islands north of Japan.
The dispute over the islands, which were seized by Soviet forces at the end of World War Two, is so acrimonious that Moscow and Tokyo have not yet signed a peace treaty to mark the end of the war.
Princess Takamado's eight-day trip will be the first time a member of Japan's royal family has visited Russia since 1916, Kyodo reported.
The princess, the widow of a cousin of Emperor Akihito, has no plans to meet with Russian dignitaries, the news agency said, but will watch the Japanese soccer team take on Colombia and Senegal in the Russian cities of Saransk and Ekaterinburg.
Japan's Imperial Household Agency and the Japan Football Association were not immediately available for comment.
