South Korean Ambassador to Japan Kwon Chul Hyun protested Japan's claim of ownership of two disputed islets on Tuesday.

During a meeting with Japanese foreign ministry officials, Kwon Chul Hyun said the matter has long been disputed and the Japanese government is further straining the relationship between Japan and Korea.

"I am filled with sadness and anger. I wonder if this was the only solution Japan could come up with."

The ambassador demanded that Japan take proper measures regarding the issue and warned Japan of "much loss" that could result from the matter.

Meanwhile, Japanese Prime Minister Yasuo Fukuda said it's reasonable for a country to have its own understanding toward its own territory. The country's foreign ministry said South Korea should calm down, and called for cooperation to deal with the differences.

The Japanese government announced on Monday its decision to describe the two disputed islets in the Sea of Japan, known as Takeshima in Japan and Dokdo in South Korea, as Japan's territory in a teaching guideline for junior high school teachers and textbook publishers. The move immediately enraged South Korea.