It would be the first time a G7 summit ends without a communique since meetings began in 1975, NHK said.

Finding common ground between allies has become increasingly tough at the annual summit with the United States an outlier in its approach to handling disputes over trade and the environment.

U.S. President Donald Trump has expressed his preference for bilateral trade pacts over multilateral agreements and is locked in a lengthy trade war with China.

Trump also pulled the United States out of the landmark Paris agreement to limit the effects of climate change against European opposition.

The summit will be held Aug. 24-26 in the southwestern France city of Biarritz. The group comprises the United States, France, Britain, Japan, Germany, Italy, Canada and the European Union. (Reporting by Chris Gallagher in TOKYO Editing by Shri Navaratnam)