A woman walks past a television screen showing file footage of a North Korean missile launch, at a railway station in Seoul. (AFP/Getty Images)

TOKYO — North Korea might be talking about building missiles that can reach the United States, but Kim Jong Un’s regime already has lots of missiles that can reach Japan. So the Japanese government is preparing its citizens in case a missile comes their way — possibly with less than 10 minutes’ warning.

The prime minister’s office issued new “actions to protect yourself” guidelines this week, including for the first time instructions on how to respond if a North Korean ballistic missile is heading toward Japan.

Three of the four missiles that North Korea launched March 6 fell within Japan’s exclusive economic zone in the Sea of Japan, the body of water that separates Japan and the Korean Peninsula. North Korea later said that it was practicing to hit U.S. military bases in Japan.

North Korea showed almost two decades ago that it has all of Japan in its reach. In 1998, North Korea fired a Taepodong-1 missile — ostensibly for launching a satellite — over Japan and into its economic zone on the Pacific Ocean side.

The Japanese government’s advice isn’t exactly helpful, amounting to basically: You won’t get the warning in time, but if you do, then go to a strong building.

As North Korea has issued threats and paraded missiles this month, Japan’s official civil defense website has had 5.7 million visitors in the first 23 days of April — compared with usual monthly traffic of less than 400,000 hits.

Under the "frequently asked questions" section, the government poses the question of how many minutes it would take for a missile to reach Japan.

“When a missile is launched from North Korea, it will not take long to reach Japan,” the answer reads. “For example, the ballistic missile launched from [North Korea] on February 7 last year took 10 minutes to fly over Okinawa.”

North Korea conducted a live-fire artillery drill to mark the founding of the country's army on April 25. The White House plans to host a private briefing on North Korea for the U.S. Senate amid growing concern over Pyongyang's nuclear program. (Reuters)

The central government has also been holding meetings to instruct local governments what they should do if a North Korean missile hits their region.

This meeting was unprecedented in post-war Japan, the Asahi Shimbun newspaper reported, marking the first time the Japanese government has taken steps to instruct residents on how to prepare for enemy attacks.

In Yamagata prefecture, which extends to the Sea of Japan, plans are underway to conduct an evacuation drill as soon as possible.

In Akita prefecture to the north, Gov. Norihisa Satake instructed his disaster management department to stay on alert around the clock this month.

To the south, in Fukui, the local government will have its staff stay on alert overnight Tuesday, in case of any provocations linked to the anniversary of the founding of North Korea’s army.

In “Actions and Other Measures In Case of Falling of Ballistic Missile” posted on its website last week, Fukui’s prefectural government told citizens to “evacuate to a substantial building or underground shopping area” if they were outside, and to lie down under cover and away from windows if inside.

Japan has a system called “J-Alert” designed to broadcast information about an imminent missile attack to disaster management officials at the local level. Here’s how The Japan Times described the system:

From there, local governments will relay warnings via outdoor loudspeaker systems, emergency broadcast channels on cable TV, FM radio broadcasts and cellphone alerts.

If you are outside when a warning is sounded or received, the government’s advice is to proceed calmly to the strongest concrete building you can quickly get to, or to go underground, if possible. Families in their homes are advised to stay low to the floor, take cover underneath tables and to stay away from glass windows.

But Osaka Mayor Hirofumi Yoshimura said that there would be almost no time to respond to a North Korean missile.

“A missile may not be detected as soon as it leaves the launch pad ... and that could take several minutes,” he said, according to the Japan Times report. “Depending on the case, the warnings and alarms might only sound four or five minutes before a missile arrives."

Meanwhile, sales of nuclear shelters and radiation-blocking air purifiers have surged in Japan, Reuters reported. A small company that specializes in building nuclear shelters, generally under people’s houses, has received eight orders in April alone compared with six orders during a typical year.

Increased efforts to make contingency plans in response to growing public concern will also likely accelerate a push by the government and the ruling Liberal Democratic Party for an upgraded ballistic missile defense system for the nation, the Asahi Shimbun wrote.

An influential group of politicians is publicly arguing for technically pacifist Japan to acquire the ability to strike North Korea instead of having to rely on the United States for its defense, and has submitted a recommendation to the government to this effect.

Yuki Oda contributed  to this report.