He also pointed out the need to review the country's disaster management system, since extreme weather is expected to become increasingly common due to the climate crisis.

Many countries across East Asia are now experiencing more intense daily rainfall, with summer monsoons expected to grow stronger and more unpredictable as the Earth warms, according to the Intergovernmental Panel on Climate Change.

Heavy rain is expected to continue on Tuesday, with up to 100 millimeters (3.9 inches) of rain per hour in some regions, according to the country's Meteorology Administration.

Parts of Japan also saw downpours on Monday night, with some regions of Hokkaido reporting flooding -- but no injuries as of Tuesday.

Authorities have warned of the risk of flash floods and landslides.