Newly appointed Defense Minister Yuriko Koike pledged Wednesday to further strengthen the Japan-U.S. military alliance but also denounced the 1945 U.S. atomic bombings of Japan as "unacceptable from a humanitarian viewpoint."

Koike takes over from Fumio Kyuma, who resigned Tuesday to take responsibility for remarks he made Saturday interpreted as justifying the atomic bombings of Hiroshima and Nagasaki in August 1945, which had killed an estimated 210,000 people — mostly noncombatants — by the end of that year.

In her first news conference Wednesday as defense chief, Koike tried to avoid the domestic political minefield of the atomic bomb issue by criticizing the nuclear attacks in the closing days of World War II as "an outright challenge to human beings."