Japan destroyer heads to Middle East
The vessel left the Yokosuka naval base, south of Tokyo, for an information gathering mission in the Gulf of Oman, northern parts of the Arabian Sea and parts of the Gulf of Aden.
Japan earlier decided not to take part in the US-led Operation Sentinel to protect shipping routes in the region.
"Securing safety of vessels related to Japan is an important duty of the government," Prime Minister Shinzo Abe told the crew members of the 4,650-ton ship - the Takanami - as it readied to leave port.
Energy-poor Japan has traditionally enjoyed warm ties with Middle Eastern countries, including Iran, as the world's third largest economy relies heavily on energy from the resource-rich region.
Abe has held a series of meetings with Middle Eastern leaders over the last year, including Iran's Supreme Leader Ayatollah Ali Khamenei and President Hassan Rouhani, in an attempt to calm the soaring tension between Washington and Tehran.
The naval destroyer will join two Japanese surveillance patrol airplanes that have been operating in the region as part of the same mission.