Korea sent back on Thursday the protest letter from the Japanese prime minister to President Lee Myung-bak over his visit to the easternmost South Korean islets of Dokdo, Seoul's foreign ministry said.
The letter from Prime Minister Yoshihiko Noda has been returned via registered mail, a rare diplomatic response, as the foreign ministry in Tokyo refused to receive it in person, a South Korean foreign ministry official said.
"We had no choice but send it by post as the diplomat from our office was prevented from passing through the door at the foreign ministry in Tokyo," the official said.
The letter is expected to be delivered the next day at the earliest.
The Korean government had planned to send the letter back via a diplomatic channel, but it fell through as Japan turned down a request for a meeting or a visit, according to the ministry.
Kim Ki-hong, an official from the Seoul foreign ministry, was denied entry at the Japanese foreign ministry later in the day, because he "did not make an appointment in advance."
According to sources familiar with the matter, Kim did make a phone call to the foreign ministry, who refused to schedule a time for a meeting.
When Kim and an interpreter arrived at the site at 3:40 p.m., security guards blocked their way by closing the iron gate, the sources said.
Noda's letter was handed to Seoul's embassy in Tokyo last Friday, describing as regrettable Lee's Aug. 10 visit to Dokdo and his remarks that Japan's Emperor Akihito should apologize for Japan's 1910-45 colonial rule if he wishes to visit South Korea.
Seoul decided to send back the letter, citing factually "incorrect and unjust" claims regarding the islets.
Diplomatic relations between the two countries have soured since Lee's visit to Dokdo.
The South Korean foreign ministry earlier in the day lodged a "strong protest" against Japanese Foreign Minister Koichiro Gemba's remarks on Wednesday that described Seoul's control of the islets as an "illegal occupation."
Dokdo, which lies closer to South Korea in the body of water between the Korean Peninsula and Japan, has long been a thorn in bilateral relations. South Korea keeps a small police detachment on the islets, effectively controlling them. (Yonhap)