A case of swine fever has been confirmed at a pig farm in Okinawa Prefecture, southern Japan.
Infection was confirmed at the farm in the city of Uruma. The disease is highly contagious among swine.
The prefectural government of Okinawa has already banned transporting pigs, and plans to proceed with culling pigs and other steps to prevent the spread of the epidemic.
The agriculture ministry says the disease has so far spread to pigs and wild boars in 13 prefectures since a case was confirmed in Gifu Prefecture in September, 2018.
The case in Okinawa was the first confirmed outside the Chubu, Kanto and Kansai regions.
The confirmation of infection in Okinawa prompted agriculture minister Taku Eto to visit the prefecture on Wednesday.
After inspecting quarantine facilities at Okinawa's Naha Airport, he expressed the government's intention to enhance the quarantine system.
He said he acknowledges the seriousness of the case, which occurred in a remote area not connect by land. He said the route of infection must be clarified and quick action will be needed to prevent further infections.
He also noted that cases of African swine fever, or ASF, have been reported in China, South Korea and elsewhere.
Eto said if ASF infection occurs in Japan, it could threaten pig farming in the country.
He said he will take every possible measure to prevent the disease from entering Japan, as the Tokyo Olympics and Paralympics will be held this year.