The government's top spokesman on Thursday accused South Korea of creating a "grave humanitarian issue" by extending its travel ban on a Sankei Shimbun reporter indicted for defaming President Park Gyeun-hye.
Tatsuya Kato has been "banned from leaving the country and his movement has been restricted. And now we are seeing (the ban) extended by three months, which is a grave humanitarian issue," Suga said.
"The government will convey our concern to the South Korean side and urge them to take appropriate action," Suga told a press conference.
Kato is the Sankei's former Seoul bureau chief. He was indicted last year but was not arrested for allegedly defaming Park in an article published online in August.
The article suggested Park was not at her office for seven hours on April 16, the day the Sewol ferry sank, killing about 300 passengers and crew. The text repeated innuendo that Park might have been in a liaison with a recently divorced former aide.
Kato cited hearsay among stockbrokers and quoted from the Chosun Ilbo, a major South Korean newspaper that first reported the rumor but has not similarly been charged with defamation.
His travel ban, which initially came into force on Aug. 7, was set to expire on Thursday.
Suga called for respect for freedom of the press, saying Kato's indictment "deviates significantly from international norms" and should not be tolerated in a democratic country.