On Thursday, Morgulov said that the issue related to the Kuril Islands "was resolved seventy years ago," and that "there is no dialogue with Tokyo on the Kuril problem."
Hajime Hayashi, head of the Japanese Foreign Minister's Europe Department, handed a note of protest to the Russian Ambassador in Tokyo Yevgeny Afanasyev on Friday, saying that Morgulov's statement is "inadmissible."
Japanese Foreign Minister Fumio Kishida was quick to say, in turn, that his country has protested what he described as "an unconstructive statement that runs counter to the truth," according to the Japanese news agency Kyodo.
At the same time, Kishida called for bolstering relations between Russia and Japan, which he said should develop a "constructive dialogue".
Japan claims these islands, referring to a bilateral Treatise on Trade and Borders signed back in 1855.
Moscow, for its part, proceeds from the assumption that the southern Kuril Islands became an essential part of the Soviet Union following the end of the Second World War and that the legally-binding Russian sovereignty over the islands cannot be questioned.