The Northern Territories occupied by Russia belong to Japan, Ukrainian Defence Minister Oleksiy Reznikov has said on Twitter, writing in Japanese.
He noted that he had a "very constructive" meeting with Japanese ambassador to Ukraine Kuninori Matsuda.
"We greatly appreciate Japanese financial&humanitarian assistance to Ukraine in this difficult time. I sent greetings to Japanese Defence Minister Yasukazu Hamada &invited him to visit Ukraine," Reznikov tweeted in English.
In April, Japan for the first time since 2003 officially said the Kuriles had been illegally occupied by Russia. In addition, the Japanese Foreign Ministry called the Russian invasion of Ukraine "violence that undermines the foundations of international order not only in Europe but also in Asia".