Japanese Prime Minister Shinzo Abe, under fire abroad for denying government involvement in forcing women to serve as sex slaves during World War Two, said on Monday he was "apologizing here and now as the prime minister."

Abe said earlier this month there was no proof Japan's government or army kidnapped women to work as "comfort women," as the wartime sex slaves are known in Japan.

He had also said he stood by a 1993 apology known as the Kono Statement that acknowledged official involvement in the brothels.

But he has said there would be no new apology even if U.S. lawmakers adopted a resolution seeking one.

"I am apologizing here and now as the prime minister, and it is as stated in the Kono Statement," Abe told a parliamentary committee in response to a question by an opposition lawmaker.

"As I frequently say, I feel sympathy for the people who underwent hardships, and I apologize for the fact that they were placed in this situation at the time."