The decision comes after US President Donald Trump and North Korea's leader Kim Jong Un met last week in Singapore and signed a joint document calling for the denuclearisation of the Korean peninsula.

"Following achievements made in the US-North Korea summit, we will halt drills involving residents for the time being," Yoshihide Suga told reporters, confirming earlier reports.

Instead, the government will shift its focus to keeping people informed about the nation's alert system and "how to behave" if missiles strike Japanese territory, said Suga.

Last year, Pyongyang fired two missiles over Japan and it has splashed others into the sea near the country, sparking a mix of panic and outrage.

North Korea has singled out Japan, a key US ally in the region, for verbal attacks, threatening to "sink" the country into the sea and to turn it into "ashes".

But the regional mood has turned towards diplomacy since the Winter Olympics in South Korea earlier this year, which set off a series of diplomatic moves culminating in the Trump-Kim meet.

Following the decision, nine drills planned for this year will be cancelled, a cabinet office official said.

Two drills have already been held this year, and 24 took place in the fiscal year to March, including one in Tokyo in January when hundreds of residents scrambled for cover at an amusement park.