South Korea on Tuesday launched a new coast guard vessel to patrol around Takeshima, the pair of islets it controls in the Sea of Japan that are claimed by Japan.

"Defending Dokdo is to defend the pride of the Republic of Korea," said President Park Geun-hye at a Coast Guard Day ceremony in Incheon celebrating the launch of the 1,000-ton vessel of the Cheongryong class, according to the presidential office.

The islets are called Dokdo in Korean.

Park said South Korea will not tolerate any challenges to its sovereignty over its islands, continental shelf and exclusive economic zone.

The new vessel is 91 meters long and can travel at speeds of up to 55 kph, according to Yonhap News Agency.