Environment Minister Yuriko Koike, resuming her official duties Monday after recovering from acute pneumonia, said she had "worked too hard" because women are not recognized in the political community unless they work 10 times as hard as men.

"Cherry blossoms at the Foreign Ministry have already turned into leaves, and it made me feel that I have been absent for a long time. I want to make a full comeback by gradually getting used to work," she told reporters after arriving at the building in Tokyo's Kasumigaseki district that houses the Environment Ministry.

Resuming her official duties, the 53-year-old Koike had a two-hour meeting with ministry officials to discuss "Cool Biz," the governmental campaign that starts in late May to encourage people to dress more casually to help cut down on power consumption.

Koike was taken to a hospital March 29 after developing a high fever. She was not released until Friday.