The Defense Ministry might divert a refueling ship engaged in U.S.-led antiterrorism operations in the Indian Ocean to back its expected antipiracy mission off Somalia, Defense Minister Yasukazu Hamada said Tuesday.

The Maritime Self-Defense Force ship is refueling destroyers from Japan and ships from other nations, but sending it to the pirate-infested Gulf of Aden might provoke criticism that the missions are being mismanaged.

"Although we are not yet at the stage to state with any certainty, we are considering various options," Hamada told a news conference.