Holding a notepad full of questions, 15-year-old Ko Yu-jeong rushes up to a South Korean diplomat after his speech, asking how she can better argue the case for her country's control of a set of islets also claimed by Japan.

Ko was one of hundreds of high-school students to be told in a lecture by Foreign Ministry officials that Japan's claims to the islets, called Dokdo in Korean and Takeshima in Japanese, amount to "nonsense."

"We want to arm you with the logic you need to convince foreigners that Dokdo is ours through this lecture," Che Dong-hwan, a Foreign Ministry official, said as he stood next to a screen showing a bird's eye view of the islets. The series of three classes for students from middle school through university ended Wednesday.

The lectures are part of a growing propaganda war in a decades-long dispute over who controls the barren rocks more than 100 miles from either mainland. The spat leapt to the front pages of both nations' media in 2012, when then-President Lee Myung-bak flew by helicopter to the outcroppings in the first visit by any South Korean president — a move that boosted his approval rating from a record low and outraged the Japanese.

South Koreans' passion for Dokdo also reflects the lingering resentment over Japan's 35-year occupation of the peninsula that continues to infuse public opinion and politics. The spat has contributed to President Park Geun-hye's refusal to meet Prime Minister Shinzo Abe, and has drawn South Korea closer to China, which has also shunned Abe over a separate island dispute and Japan's militant past.

"I don't think we should unnecessarily antagonize Japan, but Japan needs to understand its own wrongdoing and apologize about it," Ko said after the hour-long lecture, which included the screening of a video and distribution of pamphlets titled "Dokdo, Beautiful Island of Korea."

Two days before the Seoul lecture, the Defense Ministry in Tokyo released an annual report in which it described the islets as its territory, prompting an angry reply from South Korea's Foreign Ministry.

"The Japanese government should be well aware that if it continues laying unjustifiable claims to Dokdo, it will be a long time before the two countries will see improvement in their relations," the ministry said in a statement.

The spat remains a headache for the administration of U.S. President Barack Obama as it seeks to advance its rebalance to Asia and maintain a united front with its two biggest regional partners to contend with a more assertive China and North Korea's nuclear threat.

"Korea's and Japan's obsessive focus on Dokdo is the result of the strategic myopia permitted by the U.S. alliance," Robert Kelly, who teaches international relations at Pusan National University in South Korea, said in an email. "As long as the U.S. is around to insure them both against each other and their neighborhood, Korea and Japan waste a lot of time sniping at each other instead of focusing on what really matters — North Korea and China."

The islets lie about 88 km from the South Korean island of Ulleung and 158 km from Japan's Oki islands. South Korea administers the territory, maintaining a few dozen police and fisheries personnel there to bolster its claims and allowing boatloads of tourists to visit a nature reserve teeming with marine life and birds.

Next year, South Korea's Foreign Ministry plans to spend nearly 5 billion won ($4.9 million) raising awareness of the islets as its territory, up from 250 million won in 2003.

As part of the campaign the government-run Northeast Asian History Foundation this year picked both foreigners and South Koreans for cash awards in an annual essay contest with the Korea Times on "the meaning of Dokdo for Koreans." Last year, a South Korean man won 5 million won for his painting of a giant rose of Sharon — South Korea's national flower — hovering over the islets in a government-sponsored art contest.

The Foreign Ministry in Tokyo maintains a Takeshima website, explaining in 12 languages that the country established sovereignty over the islands by the mid-17th century. Shimane Prefecture, just over 200 km away, started an annual Takeshima Day in 2005 — a move that sparked protests across South Korea and prompted a man to set himself on fire outside the Japanese Embassy in Seoul.

South Korea dismisses the very notion that the islets are in dispute, citing a collection of ancient maps and documents from both nations that show Japan repeatedly acknowledged the territory as Korean.

The islands may even emerge as a symbol of unity between the two Koreas. To mark the Aug. 15 liberation holiday, a choir of about 50 North Korean defectors will join Lee Seung-chul, a South Korean pop star, on the islets to sing unification songs.