Japan plans to extend by another year the deployment of Maritime Self-Defense Force personnel to combat piracy in waters off Somalia in East Africa, a Japanese government source said Tuesday.

Prime Minister Shinzo Abe's Cabinet is expected to approve the extension in early July to help ensure the security of an important sea lane for Japan and as Tokyo's proactive contribution to maintaining international peace and stability, the source said.

MSDF escort vessels and P-3C patrol aircraft have been deployed since 2009 to help protect commercial vessels from pirate attacks in waters off the East African country. The mission has been extended every year since, as decided by the Cabinet.

In December 2013, Japan joined multinational antipiracy operations led by the United States and Britain, and sent a senior MSDF officer last month to command the multinational forces for the first time.

The size of the unit for the extended mission is expected to remain largely unchanged at two escort vessels, two P-3C aircraft and about 600 MSDF members.