Sources close to the Japanese government say Tokyo is considering new sanctions on organizations suspected of involvement in the provision of materials to Russia that could be converted for military use.
They say the sanctions could include a ban on exports from Japan to businesses in third countries, including in China.
The plan is meant to step up pressure on activities that help Russia's military operation in Ukraine.
The United States expressed concern earlier this year about Chinese exports to Russia of nitrocellulose, a dual-use material that can be used to produce ammunition.
Once the sanctions policy is in place, Japanese Prime Minister Kishida Fumio would present it to other Group of Seven countries at the summit in Italy. The meeting is scheduled to be held from Thursday.
Japan's imposition of sanctions on companies in China would be the first related to Russia's offensive in Ukraine.
Observers say the move would encourage China to act responsibly for global peace and stability.