A Cabinet member who resigned Wednesday admitted Thursday to using a free train pass for Diet members to travel to a hot spring resort to see his mistress and offered to repay the fare, Chief Cabinet Secretary Takeo Kawamura said.

Yoshitada Konoike resigned the post of deputy chief Cabinet secretary Wednesday, citing "health problems," after a weekly magazine was released the same day with an article and photos revealing his extramarital affair and reporting that he used the free pass for the trip to Atami, Shizuoka Prefecture.

On Thursday, Prime Minister Taro Aso, known for his frequent flip-flopping on the issues, reversed himself yet again and admitted he bore responsibility for appointing Konoike to deputy chief Cabinet secretary.

"I have said that I am responsible for appointments, and this case is no exception," Aso said in the evening.

On Wednesday, he had tried to avoid blame. "If it is due to health problems, I don't understand why I should be held responsible for naming him," he said.

Konoike has been in a hospital since Tuesday evening, and the government said he is suffering from interstitial pneumonia.

According to Kawamura, Konoike admitted Thursday that most of the article's content was true and it was "inappropriate" for him to use the free transport pass for private business. Konoike made the confessions when one of Kawamura's secretaries visited him at the hospital.

Citing the diagnosis, Kawamura also said Konoike is suffering from lung disease and a resultant strain on the heart and that he "needs to be hospitalized for a while."