The top diplomats and defense chiefs from Japan and the United States will gather for security talks next Sunday that will for the first time cover “extended deterrence,” or the U.S. commitment to using its military capabilities, including nuclear weapons, to protect its ally and deter attacks.

The high-level “two-plus-two” talks in Tokyo involving Foreign Minister Yoko Kamikawa and Defense Minister Minoru Kihara and their U.S. counterparts, Secretary of State Antony Blinken and Defense Secretary Lloyd Austin, have not previously grappled with the issue, which is sensitive in Japan, the only country to have been attacked with nuclear weapons.

“This will be the first time to do this at the ministerial level,” U.S. Assistant Secretary of State for East Asia and Pacific Affairs Daniel Kritenbrink told reporters Monday in Washington, adding that the talks would build on a longstanding bilateral dialogue on extended deterrence.