Hundreds of flights have been grounded and more than 200 people evacuated in South Korea as Typhoon Hinnamnor approaches the southern region with heavy rains and winds of up to 290km an hour.
The nation has been put on alert for its worst storm in decades.
South Korea's weather agency said the country will start to feel the full force of Hinnamnor, the strongest global storm this year, by early Tuesday when it is forecast to graze the southern resort island of Jeju before making landfall near the mainland city of Busan.
Government officials raised concern about potentially huge damage from flooding, landslides and tidal waves triggered by the typhoon, which comes just weeks after capital Seoul and nearby regions were hit with heavy rainfall that unleashed flashfloods and killed at least 14 people.
President Yoon Suk Yeol, who said he would stay at his office overnight to monitor the typhoon, urged maximum effort to prevent casualties during an emergency response meeting on Monday. Prime Minister Han Duk-soo called for proactive efforts to evacuate residents in areas vulnerable to flooding.
Officials say Hinnamnor could bring more powerful winds than 2003 Typhoon Maemi, which left 117 people dead and was the strongest storm to make landfall in the country since the start of record keeping in 1904.
As of Monday evening, Hinnamnor was over the open sea 240km southwest of Jeju. It has dumped more than 50cm of rain in the central part of Jeju since Sunday, where winds were blowing at a maximum speed of 124km an hour and were picking up.
South Korea's Ministry of the Interior and Safety said there were no immediate reports of casualties. At least 11 homes and buildings were flooded in Jeju while more than 200 people were forced to evacuate in Busan and nearby cities because of safety concerns.
More than 360 domestic flights and 66 ferry services were grounded nationwide as of Monday afternoon while thousands of fishing boats returned to port.
Kindergartens and elementary schools in Seoul and all schools in Busan and nearby southern regions are scheduled to be closed or shift to online classes Tuesday, officials said.
North Korea was also bracing for Hinnamnor as it reported increasingly heavy rain in all parts of the country except for its border region with China.
South Korea's military said North Korea discharged water from a dam near its border with the South in an apparent preventive step without notifying its rival. South Korea's Unification Ministry, which handles inter-Korean affairs, said the North has so far ignored Seoul's request to give notification before it releases water from the Hwanggang Dam.
Cities in eastern China suspended ferry services and classes and more than 100 flights were cancelled in Japan on Sunday as Hinnamnor passed through the region.
The typhoon is on track to move closer to eastern China later in the week.
Australian Associated Press