Visiting Japanese Prime Minister Shinzo Abe said here on Thursday that he feels "deeply sorry" for the so-called "comfort women" who were forced to serve as sex slaves for Japanese forces during World War II.

"As a person and as prime minister, I feel sympathy from the bottom of my heart to former comfort women, who experienced hardships," Abe, who arrived for talks with President George W. Bush, told some members of the U.S. Congress.

"I feel deeply sorry that they were forced to be placed in such extremely painful situations," Abe said.

Abe, who sparked anger and controversy last month by claiming there was no evidence the Japanese army directly coerced "comfort women" to become sex slaves during World War II, has since offered his apology over then Japanese government and army's involvement in the forced recruitment of women from other Asian countries to provide sex to Japanese servicemen during the war.

U.S. officials have publicly rebuked Abe for denying that the Japanese military had coerced women into sex slavery during World War II.

Abe extended his apology again over the wartime sex slavery issue on Tuesday, Japan's Jiji Press reported on Wednesday.

An estimated 200,000 women were forced to serve as sex slaves for Japanese forces during World War II, most of whom came from countries invaded by Japan at that time.