Japan has repeated its territorial claim of South Korea’s Dokdo islets in its annual Diplomatic Blue Book.

The 2013 Diplomatic Blue Book approved by the Cabinet Friday states that the Japanese government's consistent stance is that Takeshima, the Japanese name for Dokdo, belongs to Japan based on historical facts and under international law.

The blue book also mentioned Tokyo lodging a protest against former South Korean President Lee Myung-bak's visit to the islets last August.

It also noted that South Korea rejected Tokyo’s proposal to take the Dokdo issue to the International Court of Justice.

The strength of the Dokdo claims in this year's blue book is similar to 2012's version but some facts were added such as President Lee's Dokdo visit.