SEOUL, South Korea – South Korea's President Yoon Suk Yeol was in hot water Tuesday after comments he made about former colonial power Japan not needing to "kneel down" to improve ties went viral on social media. Yoon, who is on a six-day state visit to the United States, has made boosting relations with Tokyo a key plank of his administration's policy as he seeks to increase regional security cooperation in the face of rising threats from North Korea. Bilateral ties were long strained by lingering issues linked to Tokyo's brutal 1910 to 1945 colonial rule over the Korean peninsula -- including sexual slavery and forced labor -- even as Washington has repeatedly urged its two key regional allies to boost cooperation. Yoon told The Washington Post ahead of his trip that he could not accept the idea that Japan "must kneel because of our history 100 years ago" if ties between the two countries were to be improved. The comments -- including the hashtag #mustkneel -- quickly became a top trending topic on Korean language social media and Twitter, and prompted wall to wall coverage in mainstream media. Yoon's office said Tuesday that the president had meant "he can't accept the claim that improving relations with Japan is impossible unless they kneel down in a time of great need for security alliance," a presidential aide told reporters, speaking on condition of anonymity. "It is foolish to render the entire history of exchange and cooperating -- dating 1,500 years -- meaningless because of an unfortunate history spanning less than 50 years," the aide said. Seoul unveiled a plan in February to compensate victims of Japan's wartime forced labor without Tokyo's direct involvement, which has enraged some victims. The victims and their lawyers say the Yoon government's proposal falls far short of their demand for a full apology and direct compensation from the Japanese companies involved. "His comment is problematic itself. What we are asking is a sincere apology," said one YouTube commentator. Europe was able to cooperate together "only after Germany had atoned sincerely over a long period of time. Has Japan done the same?" another wrote.