The Tokyo Metropolitan Government has revealed that it is planning to build an underground missile shelter under the Azabu-Juban subway station in Tokyo¡¯s Minato Ward, in a move that comes amid heightened geopolitical tensions and concerns over national security.

¡°We have prepared other evacuation facilities in the past, but considering how rocky international affairs are right now we think it¡¯s important to prepare for the serious and significant threat of ballistic missiles,¡± Tokyo Gov. Yuriko Koike said Friday.

Azabu-Juban station is a stop along the Toei Oedo and Namboku lines, and is in close proximity to the Roppongi and Hiroo districts where many foreign embassies and office buildings are located.

The underground missile shelter will be made by converting an emergency supplies warehouse within Azabu-Juban station.

Under the Civil Protection Law, the national government requires all prefectures to assign temporary emergency evacuation spots where residents can seek shelter from a missile attack. Typical locations include the basement area of concrete buildings and underground train stations. Shelters must have enough space to afford 0.825 square meters ¡ª about 90 square centimeters ¡ª per person for the entire population of the prefecture.

As of October, Tokyo had 4,258 locations designated as temporary emergency evacuation areas. The metropolitan government is also looking to build stronger, more durable facilities that would be able to withstand prolonged, intense strikes.

While these temporary emergency shelters are located in areas deemed to be safe, they do not hold supplies needed for longer stays, such as drinking water and food.

Officials at the metropolitan government have toured bomb shelters in other countries such as Finland in order to gather ideas to increase the safety of their own temporary shelters.

¡°We would like to move forward (with our plan) using these examples as a reference,¡± Koike said.

To prepare for long-term evacuations, the shelter in Azabu-Juban is set to be equipped with an emergency power source among other tools, in addition to having a stockpile of drinking water and food.

Around ?165 million will be set aside by the metropolitan government in next year¡¯s budget for expenses related to the project, such as research fees.

The exact date for the project¡¯s completion remains unclear.