Tokyo ? Japan’s nationalist prime minister denied Thursday that the country’s military forced women into sexual slavery during World War II, casting doubt on a past government apology and jeopardizing a fragile detente with his Asian neighbors.

The comments by Shinzo Abe, a member of a group of lawmakers pushing to roll back a 1993 apology to the sex slaves, were his clearest statement as prime minister on military brothels known in Japan as “comfort stations.”

Historians say some 200,000 women – mostly from Korea and China – served at the Japanese military brothels throughout Asia in the 1930s and 1940s. Many victims say they were kidnapped and forced into sexual slavery by Japanese troops.

But Abe, who since taking office in September has promoted patriotism in Japan’s schools and a more assertive foreign policy, said there was no proof the women were forced into prostitution.

“The fact is, there is no evidence to prove there was coercion,” Abe said.

His remarks contradicted evidence in Japanese documents unearthed in 1992 that historians said showed military authorities had a direct role in working with contractors to forcibly procure women for the brothels.

The documents, which are backed up by accounts from soldiers and victims, said Japanese authorities set up the brothels in response to uncontrolled rape sprees by invading Japanese soldiers in East Asia.

In 1993, then-Chief Cabinet Secretary Yohei Kono apologized to the victims of sex slavery, though the statement did not meet demands by former “comfort women” that it be approved by parliament. Two years later, the government set up a compensation fund for victims, but it was based on private donations – not government money – and has been criticized as a way for the government to avoid owning up to the abuse.

The mandate for the fund is to expire March 31.

Abe’s comments were certain to rile South Korea and China, which accuse Tokyo of failing to fully atone for wartime atrocities. Abe’s government has been working to repair relations with Seoul and Beijing.

The statement came just hours after South Korean President Roh Moo-hyun marked a national holiday honoring the anniversary of a 1919 uprising against Japanese colonial rule by urging Tokyo to come clean about its past.