South Korea is expected to reiterate its stance on the issue of Dokdo and refute Japan's sovereignty claim in its reply to a letter by Japan's prime minister to President Lee Myung-bak, two government officials said Sunday.

Japanese Prime Minister Yoshihiko Noda sent the letter to Lee via Seoul's Embassy in Tokyo on 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.

The letter was sent on the same day South Korea dismissed a Japanese proposal to jointly take the issue of Dokdo, Seoul's easternmost islets claimed by Tokyo as its territory, to the International Court of Justice (ICJ) as being "not even worthy of consideration."

"It would be inappropriate for us not to reply or send back the letter signed by the (Japanese) prime minister. So, we think that it is appropriate to send a response letter to Japan," a senior government official said on the condition of anonymity.

Another senior official said, "It will be difficult for us not to make any reaction to the letter by the Japanese prime minister because it was a kind of action."

The timing and content of the possible reply to Noda will be decided after watching reactions by Japan over the issues, according to the officials.

Earlier in the day, a diplomatic source in Tokyo said that Japan is expected to deliver a diplomatic letter this week repeating the proposal to refer the issue of Dokdo to the ICJ.

Noda will hold a Cabinet meeting on Tuesday to make a decision on whether to send a "note verbale," a diplomatic document unsigned but more formal than a verbal proposal, to South Korea, the source said on the condition of anonymity.

Rejecting the proposal, South Korean Foreign Ministry spokesman Cho Tai-young made it clear that, "As Dokdo is clearly an integral part of Korean territory, historically, geographically, and under international law, there is no territorial dispute over it."

Cho also warned that South Korea will "deal sternly with any provocation by Japan over Dokdo."

Seoul officials said the Japanese proposal is not feasible because Tokyo must secure Seoul's consent to refer the issue to the ICJ.

Although it was the first time since 1962 for Japan to make such a proposal to South Korea, Seoul will make a cool-headed response to the proposal, as it does not want to be mired into a ploy by Tokyo to make Dokdo a disputed territory, officials said.

Japan's claims to Dokdo have long been a thorn in relations between South Korea and Japan. South Korea keeps a small police detachment on the islets, effectively controlling them.

South Koreans see Japan's claims as amounting to denying Korea's rights because the country regained independence from the Japanese colonial rule and reclaimed sovereignty over its territory, which includes Dokdo and many other islands around the Korean Peninsula. (Yonhap News)