South Korean President Moon Jae-in strongly urged Japan to sincerely reflect on its past wrongdoings on Wednesday, also saying the country has no right to claim settlement of its sexual slavery of Korean women, despite the countries' 2015 deal that he called flawed.

"Also in resolving the issue of sexual slaves, the Japanese government, the perpetrator, must not say it is 'over'," the president said in a speech marking the anniversary of the 1919 March 1 Movement, in which tens of thousands of Koreans staged street rallies to declare the country's independence from Japan's colonial rule.

The ceremony was held at Seodaemun Prison, which was used by Japan's colonial government to hold and persecute nearly 100,000 Korean independent fighters during its 1910-45 colonial rule of Korea.

Moon's remarks come amid Tokyo's repeated calls for the new South Korean president and his administration to honor the 2015 agreement made with South Korea's ousted administration. Under the pact, the former Park Geun-hye administration agreed to "finally and irreversibly" settle the issue in exchange for 1 billion yen ($9 million).

Moon earlier declared the controversial agreement "seriously flawed."

"Inhumane violation of human rights during war cannot be covered by saying it is over," he said in the event marking the 99th anniversary of the March 1 movement.

"A true resolution only comes from remembering history and learning from that history, especially when it is history of an unfortunate past," the president added.

The president said what his country and its victims wanted to see from Japan was a sincere apology.

"I wish Japan will truly make up with its neighboring countries that it oppressed and together walk the path of peaceful co-prosperity. I do not demand special treatment from Japan. I simply want Japan to move into the future with us based on its sincere reflection and apology," Moon said.

Japan expressed regret about Moon's remarks.

Chief Cabinet Secretary Yoshihide Suga said during a regular press briefing that the remarks were "extremely regrettable" and that the country immediately filed a complaint with the South, according to media reports.

He also urged Japan to stop making its territorial claim to South Korea's eastern-most island of Dokdo.

"Dokdo is our land that was first occupied in the process of Japan's invasion of Korea. It is our native territory," the president stressed.

"Japan denying this fact is same as its refusal to reflect on its imperial invasion (of Korea)," he added.

Saying the country's own efforts were what had won its independence from the Japanese colonization, the president called for efforts to ensure peace on the Korean Peninsula.

"While moving toward the 100th anniversary of independence, we must complete building a joint community of peace, a joint economic community on the Korean Peninsula. We will have to make sure that division (of the two Koreas) will no longer be an obstacle to our peace and prosperity," he said. (Yonhap)