Responding to questions about the drills, Japanese Prime Minister Shinzo Abe told reporters earlier on Wednesday that "our country, for its part, can't accept this at all".
The exercises came after Russia scrapped a meeting with a Japanese minister in response to a new round of sanctions by Tokyo against senior figures involved in the annexation of Ukraine's Crimean peninsula.
The exercises are "extremely regrettable," said a foreign ministry spokesman on Wednesday. "We have filed a stern protest with the Russian embassy," he added.
Read more here: Business Spectator