Photo/Illutration South Korean Foreign Minister Kang Kyung-wha, right, meets with Japanese Ambassador to South Korea Koji Tomita at the Foreign Ministry in Seoul on March 6. (AP Photo/Pool)

SEOUL--South Korea issued a strongly worded protest on Friday against Japan’s decision to quarantine South Korean visitors for two weeks, as coronavirus containment measures ignited a fresh diplomatic row between the Asian nations.

Japan joined the list of almost 100 countries that have imposed restrictions on South Korean travelers, barring arrivals from highly affected areas starting on Saturday and ordering a two-week quarantine for those from other regions.

The South Korean foreign ministry said Japan’s ambassador would be summoned to explain Tokyo’s decision and receive a formal complaint. Seoul has previously summoned ambassadors from Vietnam and Singapore over similar travel restrictions.

“It is extremely regrettable Japan took this unreasonable and excessive step without sufficient prior consultation with us, and we strongly urge immediate reconsideration,” it said.

After a meeting at the presidential Blue House, the National Security Council (NSC) issued a statement saying Tokyo faced “mistrust from the international community due to its opaque, passive” response to the coronavirus outbreak.

“We will explore necessary countermeasures based on principles of reciprocity,” it said.

Japan’s chief government spokesman, Yoshihide Suga, defended the travel restrictions which also apply to visitors from China.

“The decision was the result of a comprehensive review of the information available about the situation in other countries and the effects of other measures,” he said.

“I think the timing is appropriate.”

The row came as the number of new cases in South Korea, the country with the biggest outbreak of the flu-like virus outside China, fell to 196 from 760 the previous day, for a total of 6,284 infections. The death toll rose by seven to 42, the Korea Centers for Disease Control and Prevention (KCDC) said.

The U.S. Forces Korea reported a new case for a total of seven among soldiers, employees or people related to the roughly 28,500 U.S. troops stationed in South Korea.

Vice Health Minister Kim Gang-lip said authorities had almost completed testing more than 200,000 followers of a church in the southeastern city of Daegu at the center of South Korea’s outbreak.

“It is difficult to predict future developments because there are secondary and tertiary infections happening around the country involving them,” Kim told reporters.

More than 90 percent of confirmed cases in South Korea have been found in Daegu city and nearby North Gyeongsang province. Smaller clusters of infections have been found in other regions, including a new one reported on Friday at a hospital in Seongnam southeast of Seoul.

The number of South Koreans visiting Japan fell nearly 26 percent last year from 2018 to 5.6 million, the first drop since 2011 when Japan was hit by an earthquake and nuclear disaster, according to the Japan National Tourism Organization.

Japan and South Korea have had difficult relations since Japan’s 1910-45 occupation of the Korean Peninsula. Last year Tokyo slapped trade curbs on South Korea and South Koreans responded with a boycott on Japanese goods and services.