TOKYO (Kyodo) -- The Maritime Self-Defense Force has refueled U.S. ships patrolling to counter North Korean missile launches under new security laws that took effect last year, a Japanese government source said Thursday.
The refueling missions to U.S. Aegis ships sailing in the Sea of Japan were conducted multiple times since April, making them the second instance in which Japanese Self-Defense Forces were known to have performed their expanded roles under the security legislation.
The legislation has loosened the constraints of Japan's war-renouncing postwar Constitution imposed on the activities of the defense forces, setting the stage for U.S. and Japanese troops to work more closely than ever.
Top government spokesman Yoshihide Suga said the SDF personnel are engaging in activities to provide supplies to the U.S. military based on the legislation, but refrained from acknowledging specific operations.
"I cannot comment on the issue because it will unveil the details of the operations of the SDF and the U.S. military," the chief Cabinet secretary said at a regular press conference.
In May, the MSDF engaged in a mission to protect a U.S. Navy vessel off Japan for the first time under the legislation, although Tokyo has also not officially confirmed that operation to avoid impacting U.S. military activities and bilateral relations.
According to the government source, the MSDF carried out the replenishment operations after a revised Japan-U.S. agreement on logistical cooperation between their forces took effect in April, reflecting the changes brought by Japan's legislation.
Japan's MSDF and U.S. Aegis ships equipped with ballistic missile defense systems are engaging in patrolling activities around the clock to keep watch on North Korea, which has repeatedly test-fired missiles.
Japan had conducted refueling missions to its key ally also in the past, but they were only possible through the enactment of a special law or certain occasions such as during Japan-U.S. joint exercises.
For about eight years after the 2001 terrorist attacks in the United States, the SDF refueled ships assisting U.S.-led antiterrorism operations in the Indian Ocean near Afghanistan under a special measures law.
Under the new security legislation, however, the SDF can provide oil and other supplies more flexibly than before, such as to U.S. ships involved in operations to intercept ballistic missiles and counter-piracy activities.
Japanese Prime Minister Shinzo Abe has said the legislation is intended to let Japan more actively contribute to peace and stability of the region, but it has remained controversial among members of the public who think it undermines Japan's postwar pacifism.