South Korean Prime Minister Chung Se-kyun said the move amounted to a full entry ban. “(We) consider this as very regrettable and demand the excessive and irrational measure to be immediately withdrawn.”
Relations between South Korea and Japan last year sank to their lowest point in decades as they feuded over trade issues, wartime history and military cooperation.
South Korean Foreign Minister Kang Kyung-hwa summoned Japanese Ambassador Koji Tomita to protest Japan’s move and described it as "unscientific," citing progress in the country's quarantine efforts.
South Korea has confirmed more than 6,000 cases of infection with the new coronavirus, but its numbers of new cases have been declining in recent days.
Tomita replied that Japan was facing a “critical period” that would determine whether it successfully stems the spread of the virus. Japan counts more than 1,000 cases, including about 700 from a cruise ship.
The possible countermeasures South Korea will consider include designating Japan as a risk area for infectious diseases and placing its own restrictions on travelers from Japan. However, South Korea has not taken any tit-for-tat steps against more than 90 other countries that banned or restricted visitors from the country.