Yuriko Koike became Japan's defense minister at a confirmation ceremony Wednesday afternoon, succeeding Fumio Kyuma who resigned Tuesday over his controversial remarks on the U.S. atomic bombings of Japan in World War II.

Koike, 54, special security adviser to Prime Minister Shinzo Abe, became the first woman to assume the top defense post in the cabinet. Abe appointed her Tuesday after accepting Kyuma's resignation in a swift move apparently aimed at limiting any adverse impact on the July 29 House of Councillors election.

Koike separately said to reporters she will make efforts to heighten public trust in the Abe administration and the government on the whole, adding Japan must steadily work on building its defense power in light of the security situation in the East Asian region.

She also said she wants to continue the ongoing dialogue with the United States and emphasized the importance of making the Defense Ministry a more "mobile organization" and boosting the morale of its staff and SDF members to prevent scandals from happening again.

Koike is set to arrive at the ministry later Wednesday afternoon and hold a press conference in the evening.

Prior to Koike's arrival, the Defense Ministry held a farewell ceremony for Kyuma in the morning, with the outgoing minister thanking members of the ministry and the Self-Defense Forces for their services.

Kyuma, 66, faced strong criticism not only from opposition parties but also within Abe's ruling coalition parties for his weekend remarks which were taken as justifying the atomic bombings of Hiroshima and Nagasaki in August 1945, dealing another blow to the already embattled Abe ahead of the July election.