While Japan maintains sanctions on Russia over the crisis in Ukraine, Prime Minister Shinzo Abe is preparing for a visit to Japan by President Vladimir Putin this year for two reasons — to move forward the stalled territorial negotiations and the other to drive a wedge between Moscow and Beijing.

As the security environment in East Asia has become increasingly severe partly because of China's rising territorial ambitions and military buildup, Japan doesn't want to push Russia further to the Chinese side, according to Japanese officials.

This is especially important when the frequency that Air Self-Defense Forces jets have scrambled against unidentified aircraft approaching Japan — many of which are believed to be from China and Russia — has jumped seven times over the past 10 years, they say.