Foreign and defense chiefs from Japan and the United States have gathered in Washington to ensure the effectiveness of Japan's new defense policy, which gives the country the capability to launch counterstrikes.

The "two plus two" talks began on Wednesday, local time.

Japan's Foreign Minister Hayashi Yoshimasa and Defense Minister Hamada Yasukazu are meeting their US counterparts, Secretary of State Antony Blinken and Defense Secretary Lloyd Austin.

The Japan side is expected to explain revisions to key security documents that will give Japan the ability to launch counterstrikes.

The two sides are expected to agree to discuss what roles to play to best utilize that capability.

As Japan faces the challenge of establishing a defense system in space, the two sides are expected to confirm the need to include outer space in Article Five of the Japan-US Security Treaty. The article obliges the United States to defend territories under Japan's administrative control.

The US government is set to reorganize the Marine Corps stationed in Japan's southern prefecture of Okinawa and set up a new unit that will respond to military threats to the remote islands.

The move comes amid the growing Chinese presence in the East China and South China seas.