Japan is arranging to deploy four F-35A advanced stealth fighter jets by 2025 at the earliest to an Air Self-Defense Force base on the Sea of Japan coast, government sources said Wednesday, in a bid to boost the country's defense capabilities against airspace incursions by China and Russia.

The government plans to eventually deploy around 20 F-35As to Komatsu Air Base in Ishikawa Prefecture, the sources said. Japan has already decided to acquire a total of 105 F-35As, with the aim of making the aircraft one of its mainstay jets.

Chief Cabinet Secretary Katsunobu Kato said at a news conference that bases where fighter units are stationed are mainly being considered for F-35A deployment, and the Komatsu base is a "potential candidate site."

The government will notify the Ishikawa Prefectural Government and the city of Komatsu as early as Thursday, according to the sources.

The Komatsu base is home to the sole fighter unit along the Sea of Japan, with the sea separating it from countries such as China and Russia. Some 40 F-15 fighter jets are stationed at the base.

Japan has begun deploying F-35As, used by the U.S. Air Force, to replace the F-15.

The F-35A is equipped with high-performance radar that can detect ballistic missiles and is also capable of evading radar detection.

F-35As have already been deployed to Misawa Air Base in Aomori Prefecture to respond to airspace incursions and engage in surveillance activity targeting North Korea.