The government and the ruling Liberal Democratic Party on Wednesday condemned a visit to Crimea by former Prime Minister Yukio Hatoyama, saying it contradicts Japan's policy of not recognizing the Ukrainian territory's unification with Russia last year.

"As a politician who experienced the post of prime minister, it was much too hasty an act. It is extremely regrettable," Chief Cabinet Secretary Yoshihide Suga said at a news conference of Hatoyama's Tuesday visit to the Black Sea peninsula. "We would like to criticize him severely."

The government had urged Hatoyama not to visit Crimea, saying that a trip by a former prime minister with a Russian visa could conflict with Tokyo's stance that Moscow unilaterally joined the territory against international law.

Japan has joined US and EU imposing sanctions against Russia for taking Crimea and Russia's role in Ukrainian conflict.

After Crimea's unification with Russia, Japan almost immediately suspended talks on investment and visa reform as part of a sanctions package against Russia at that time.