Japan plans to dispatch Self-Defense Forces ships and patrol planes to the Gulf of Oman, the northern Arabian Sea and the eastern part of the Bab el-Mandeb Strait, but will not join a U.S.-led coalition meant to protect shipping interests in the strategic Mideast waterways, Chief Cabinet Secretary Yoshihide Suga said Friday.

The top government spokesman said Tokyo will dispatch the SDF units for "investigation and research missions" to gather information in the region.

Later in the day, Defense Minister Taro Kono said Tokyo currently doesn't believe that the security situation in the Mideast is so tense that the units might engage in military operations to defend Japan-related tankers.