So far this year North Korea has carried out 14 missile tests, all of them fired towards the coast of Japan.
Now for the first time in more than 70 years villagers along the north-west coast of Japan are being ordered to take part in air raid drills.
The BBC’s Rupert Wingfield-Hayes took part in one in the little town of Sakata.
Japan is an island country in East Asia located in the northwest Pacific Ocean. Part of the Pacific Ring of Fire, Japan comprises an archipelago of 6,852 islands covering 377,975 square kilometers (145,937 sq mi); the country’s five main islands, from north to south, are Hokkaido, Honshu, Shikoku, Kyushu, and Okinawa. Tokyo is Japan’s capital and largest city.
Japan is divided into 47 administrative prefectures and eight traditional regions. The Greater Tokyo Area is the most populous metropolitan area in the world, with more than 37.4 million residents.
Japan is a great power and a member of numerous international organizations, including the United Nations (since 1956), the OECD, and the G7. Japan is a leader in the automotive and electronics industries.