The United States has agreed to discuss with Japan a possible special bilateral pact that would address environmental pollution or destruction at U.S. military bases in Japan, the governor of Japan's Kanagawa Prefecture said Friday.

The agreement emerged when Kanagawa Gov. Shigefumi Matsuzawa and Okinawa Gov. Hirokazu Nakaima held separate talks with senior U.S. Defense and State department officials, Matsuzawa told a joint news conference with Nakaima in Washington.

"We have won a full understanding that our proposed special environmental pact will contribute to strengthening the foundation of the Japan-U.S. alliance," Matsuzawa said.

He said such a pact, if concluded, will be the first step toward an eventual goal of revising the bilateral Status of Forces Agreement, which governs U.S. military operations in Japan and legal arrangements for its personnel.

The SOFA gives virtual extraterritorial rights to U.S. personnel and there are growing calls for a revision to ensure that suspects in criminal cases are handed over to Japanese police.