US Deputy Secretary of State Kurt Campbell says the leaders of Japan and the United States are expected to agree next week to step up cooperation on joint development and production of defense equipment.

Campbell spoke at a Washington think tank on Wednesday, a week before a summit between Japanese Prime Minister Kishida Fumio and US President Joe Biden in the US capital.

He said, "the most important developments on the global stage will play out next week here in Washington as we undertake this massive modernization of the US-Japan relationship."

He added, "One of the things that I think you'll see next week are steps, for the first time, that will allow the United States and Japan to work more collaboratively on joint development and potentially co-production of vital military and defense equipment."

Arrangements are being made for the two leaders to confirm they will review the command and control framework for Japan's Self-Defense Forces and US forces in Japan, to enable their smooth cooperation.

The two leaders are also expected to discuss cooperation on economic security, and aim to boost deterrence and response capability of the Japan-US alliance.