TOKYO — The Japanese government opened a small museum Thursday displaying maps and documents to defend its territorial claims against neighbors South Korea and China.

The Japanese minister in charge of territorial issues, Tetsuma Esaki, said it was important for Japan to improve how information about disputed islands “is transmitted both internally and externally, so as to ensure as widely as possible that our claims are understood correctly.

The National Museum of Territory and Sovereignty displays replicas of historic documents that Japan says show its ownership of two sets of uninhabited islands, one also claimed by China and the other by South Korea.

The dispute with China has heated up in recent years, with Chinese coast guard ships sailing near the islands and their Japanese counterparts trying to chase them away.

The islands, which are near Taiwan, are known as the Senkaku in Japan and as the Diaoyu in China. Taiwan also claims them.

Japan has long feuded with South Korea over another group of tiny islands in the waters between the two countries. Japan calls them Takeshima, and South Korea calls them Dokdo.

South Korea denounced the opening of the museum and demanded that Japan shut it down.

“The Japanese government should immediately stop making pointless claims over Dokdo, which by history, geography and international law is clearly part of our territory,” Foreign Ministry spokesman Noh Kyu-duk said in a prepared statement.

South Korea opened a museum in central Seoul in 2012 to back its claim to Dokdo. Visitors can walk around a large 3-D model of the island and examine video and computerized content on the island’s history and nature. Video screens show live footage of the island from a fixed camera.

The opening of the Japanese museum comes two weeks before Prime Minister Shinzo Abe is set to visit South Korea to meet with President Moon Jae-in and attend the opening ceremony of the Winter Olympics in Pyeongchang.