Japanese warships are due to leave on Saturday on an anti-piracy mission off Somalia, in an operation that could see Japan's armed forces face combat abroad for the first time since World War II.
The two destroyers -- the 4,650-tonne Sazanami and 4,550-tonne Samidare -- are set to leave the port of Kure, western Hiroshima prefecture, following a ceremony to be attended by Prime Minister Taro Aso and Defence Minister Yasukazu Hamada.
The warships, each with 200 crew and carrying two patrol helicopters and two speedboats, will sail for the Gulf of Aden to protect cargo ships near the Suez Canal, which links Europe with Asia.
It is Japan's first maritime mission that could face combat abroad since the country adopted a the pacifist constitution after World War II.
Under the constitution, the mission will allow its soldiers to use force only for self defence and to protect Japanese nationals.
The Japanese government is preparing a new law that would widen the scope of force its military personnel can use against pirates and allow them to protect foreign vessels and nationals as well as Japanese.
As the ships leave Kure port, some protesters, including survivors of the US atomic bombs, plan to stage demonstrations against the deployment.
The ships are expected to arrive in waters near the Suez canal in two or three weeks.