The war in Ukraine has taken on a different aspect since North Korea sent troops to Russia, former Japanese Ambassador to Ukraine Kuninori Matsuda has said in an interview.

Joint exercises between Russian and North Korean troops are Pyongyang's "de facto participation in the war," said Matsuda, who served in the post for about three years starting in October 2021.

North Korea's participation in the war will give the country, which has not engaged in wars since the Korean War, battlefield experiences needed to boost its military capabilities, he said.

He said that there is now "a risk that North Korea will engage in adventuristic activities on the Korean Peninsula," warning of serious implications for Japan's security.

Matsuda also voiced concerns that Russia may try to change the status quo in the Far East by joining forces with North Korea.

Japan needs to act quickly to counter such a security threat in East Asia in cooperation with the United States and South Korea, he said.

The Ukraine war is "an issue for Japan and having Ukraine overcome the crisis will help Japan protect its lasting peace and prosperity," he said.

Aiding Ukraine is "an investment in our future," Matsuda added.

Matsuda said that the Ukrainian government is considering resuming commercial flights to and from Lviv that have been suspended since Russia's invasion of Ukraine in February 2022.

He added that proposed tax and investment treaties between Japan and Ukraine are likely to help companies in the two countries expand operations.