MOSCOW - Japan's deployment of offensive weapon systems in the region of frontier islands disrupts regional security and stability, posing a serious threat to neighboring countries, Russian Foreign Ministry spokesperson Maria Zakharova said Thursday.

Russia's observations show that Japan, under Washington's dictates, is systematically transforming these islands, specifically Okinawa, into a military outpost, arming it with weapons that possess not only defensive but also offensive capabilities, she said.

Tokyo's "aggressive militarist course" and such military moves "further escalate tensions in the field of regional security, pose serious risks to neighboring countries, and at the same time justify a firm response to the implementation of Japan's specific plans in this area", she said.

The Russian foreign ministry spokesperson made the remarks at a regular news briefing when responding to a Xinhua reporter's question regarding recent Japanese moves to deploy medium-range missiles on islands near China's Taiwan.

She noted that Japan's deployment of US-made medium-range missiles on the relevant islands is unacceptable.

"We are closely monitoring all statements and actions by Japan's leadership in the context of the remilitarization course it has embarked on," Zakharova said. "Earlier, we have repeatedly drawn attention to the negative impact of Tokyo's such policy on stability and security in our shared region."

"Through diplomatic channels, including the delivery of a relevant note by the Ministry, we have issued a stern warning to Japan that the deployment of US-made medium-range missiles on its relevant territory is unacceptable, regardless of the pretext, whether on a permanent, temporary, or other basis," she noted.

Meanwhile, the spokesperson urged the Japanese government led by Prime Minister Sanae Takaichi to "return to the foundations on which Japan's post-war peaceful development is built".

"These foundations are enshrined in the outcomes of World War II -- foundations that, unfortunately, as we are once again compelled to note, have not yet been fully acknowledged by Japan," she said.