TOKYO, May 3 (Xinhua) -- Japan's Maritime Self-Defense Force (MSDF) Sazanami destroyer has joined the Izumo helicopter carrier in escorting a United States Navy vessel, marking the first time such a protection mission has taken place under the controversial new security legislation, sources said Wednesday.
The Sazanami joined the mission having departed from a MSDF base in Kure, Hiroshima Prefecture, on Tuesday, Kyodo News quoted government and other sources as saying.
Japan's Ministry of Defense (MOD) previously said the inaugural mission, since the contentious new legislation took effect last year, is aimed at a showing of Japanese force alongside that of the United States.
It is also to show that the Japan-U.S. alliance stands firm amid rising tensions on the Korean Peninsula, the MOD said.
The security legislation that took effect last year which follows looser, more ambiguous constraints imposed on Japanese forces here, in contravention of Japan's war-renouncing constitution, allows for SDF members to escort and guard vessels and weapons that belong to U.S. forces.
The protection mission proviso comes into play when the U.S. activities are deemed to be beneficial to the defense of Japan.
In this case, the mission, ordered by Defense Minister Tomomi Inada, was made as the two countries may be engaged in joint exercises or the monitoring and information-gathering activities related to missile launches by the Democratic People's Republic of Korea (DPRK).
The helicopter carrier, Izumo, the largest warship Japan has entered into service since WWII, and widely regarded as de facto aircraft carrier, left its base in Yokosuka, south of Tokyo, on Monday morning for the mission.
The Izumo, which is 248-meters in length and weighs 19,500 tons, joined the the U.S. Navy supply ship off the Boso Peninsula in Chiba Prefecture, east of the capital, government sources said on Monday.
They said it will sail for two days in the Pacific toward waters off the Shikoku region in western Japan.
After escorting the U.S. ship, the Izumo, which is able to accommodate 14 helicopters and is also believed to be able to launch the controversial Osprey, as well as F-35B fighter jets from its lengthy flight deck, will continue on a three-month voyage to the Philippines and elsewhere.
On May 15, both MSDF vessels are scheduled to take part in an event in Singapore, sources here said Wednesday.
The U.S. ship, meanwhile, is expected to provide fuel for U.S. naval vessels on guard against any provocations from the DPRK, government officials here said.
The United States Carl Vinson aircraft carrier Strike Group and MSDF vessels entered the Sea of Japan off the Korean Peninsula on Saturday to carry out joint exercises, ministry officials here confirmed.
The latest actions of the MOD and the Maritime Self-Defense Force in particular deploying hardware and personnel into regions where there might be "infringements" threaten to invalidate Japan's pacifist constitution.
The constitution states that the Japanese people "forever renounce war" and ban the "use of force" as a means of settling international disputes. It also states that "land, sea, and air forces, as well as other war potential, will never be maintained."