Hashimoto's comments come amid growing fears that Japan's political leaders are increasingly shifting to the right. Conservative Prime Minister Shinzo Abe, while acknowledging the existence of comfort women, has also denied they were forced into prostitution, and advocated revising the 1993 statement, prior to taking office in December.
In a move aimed at quieting growing outrage in the region, Abe's cabinet on Friday passed a resolution reaffirming their support for that resolution.
Responding to Hashimoto's comments Monday, South Korea's Foreign Minister Yun Byung-se said summit level talks and high-ranking exchanges would be difficult, if the current atmosphere did not improve.
"Lately, Japan has continued with words that reverse course of history," he said. "[Those words] pour cold water on efforts to strengthen ties [between Japan and Korea]."
Hashimoto has become one of Japan's most prominent politicians since establishing the Japan Restoration Party last year, with former Tokyo Gov. Shintaro Ishihara. With 54 seats in the 480 seat lower house of parliament, the JRP is the second-largest opposition party, but the party's approval ratings have taken a hit, amid the controversy surrounding Hashimoto.
In a poll published by the Nikkei newspaper Monday, just 3 percent said they planned to vote for the party in July's upper house election, down from 6 percent from last month.
Asked whether he intended step down from party leadership to take responsibility for his comments, Hashimoto said he would leave that decision up to voters.
"If the voters do not support my comments, the result will be apparent in the upper house elections," he said.
The Associated Press contributed to this report.