Montgomery County in the U.S. state of Maryland is expected to use the names East Sea and Sea of Japan for the body of water lying between South Korea and Japan in its public school textbooks.

The co-chairman of an ethnic Korean civic group in the U.S. says the Montgomery education board gave the notice to all public school principals in the county Friday.

The notice says South Korea and China believe that calling the body of water the Sea of Japan only is teaching inaccurate history and hurting their national pride.

Ninety percent of public school textbooks in the U.S. use the name Sea of Japan only. Several publishers began to use both names from 2007.