Foreign Minister Yun Byung-se urged Japan on Thursday to “start off on the right foot”to repair bilateral ties ― a thinly veiled swipe at Tokyo’s approval of textbooks laying claim to the South Korean islets of Dokdo.

Yun made the remarks a day after South Korea lodged a strong protest with Japan over the approval of high school textbooks that “still contain Japan’s unjustifiable claims to Dokdo.”

“As for bilateral relations with Japan, it is always important for the two sides to start off on the right foot, including the issue of textbooks,” Yun said.

On Wednesday, Yun’s ministry summoned Japan’s second highest-ranking envoy in Seoul and delivered a letter of protest demanding Japan immediately correct the textbooks.

Ministry spokesman Cho Tai-young requested Japan to “keep in mind that textbooks, which are not based on honest reflection of past history” and the approval of the textbooks “will make its future generations carry a heavy burden of history in the end, by instilling erroneous historical views into them.”

Cho stressed that, “In order for the two countries to restore the trust between them, the Japanese government should heal the wounds of the past as soon as possible by looking squarely at its past and acting in a responsible manner.”

Dokdo, a group of rocky outcroppings lying in the East Sea between the two countries, has been a source of diplomatic tension between the two countries for years.

Japan has long laid claims to Dokdo in the country’s school textbooks, government reports and through other avenues, stoking enmity in South Korea against its former colonial ruler. South Korea views the claims as a sign that Japan has not fully repented for its imperialist past.

South Korea also says the territorial claims amount to Japan denying Korea’s independence from its 1910-45 colonial rule, because Korea had reclaimed sovereignty over its territory ― including Dokdo and many other islands around the Korean Peninsula ― when it regained independence.

South Korea has kept a small police detachment on Dokdo since 1954.

Yun is set to make a three-day visit to the U.S. next week for consultations on North Korea as well as bilateral issues in the run-up to a U.S. visit by President Park Geun-hye in May.

During the visit from Tuesday, Yun will hold his first bilateral talks with U.S. Secretary of State John Kerry. Yun’s trip is deemed unusual as Kerry plans to visit Seoul next month, meaning they will have two separate meetings in as many weeks.

“Although Secretary of State Kerry will visit Korea in the middle of next month, it will be helpful for us to meet with high-ranking U.S. officials and explain to them about the policy directions of our new government,” Yun said.

This week, Yun’s ministry set out details of Park’s “trust-building” process with North Korea, summarizing it as a three-step approach in which South Korea will first provide humanitarian aid to North Korea while calling for the North to keep the agreements made with the South.

If the first-stage measure is successful in building confidence between the two Koreas, South Korea will expand inter-Korean economic cooperation without linking it to the North’s denuclearization actions, ministry officials said.

The third-stage step is for large-scale government assistance, but it will be possible only if North Korea demonstrates its sincerity for denuclearization through actions, officials said.

Yun cautioned against reading too much into the step-by-step process, saying there will be no change in his government’s efforts to denuclearize North Korea.

“We should take a look at the big picture of the trust-building process,” Yun said. (Yonhap News)