Former Latvia President Vaira Vike-Freiberga, who gave up a slice of the Baltic republic's territory in a 2007 border dispute with Russia, emphasized the importance of national strength when negotiating with Moscow over disputed territories.

Asked what Japan can do about its territorial dispute with Russia, the former leader drew on 17th century French fabulist Jean de La Fontaine.

"The argument of the strongest one somehow seems to be always the best," Vike-Freiberga said. "In other words, those (who) are strongest win arguments simply by strength."