Two Russian fighter jets violated Japanese airspace on Thursday as Tokyo scrambled its own planes in response, the defence ministry said, reportedly the first such incident in five years.

A Russian official denies the violation.

The Russian SU-27.

"Flights by the air force of the Pacific Fleet take place regularly in this region, in strict adherence to the international rules, without violation of state borders," the spokesman of the Russian military command's eastern district Roman Martov said in a statement to Russian news agencies.

The Russian planes were detected off the coast of northernmost Hokkaido island for just over a minute, shortly after Japan's new prime minister said he wants to find a "mutually acceptable solution" to a decades-old territorial row between the countries.