Diomede Islands (DEI-yo-meed), pair of rocky isls. in Bering Strait bet. Alaska and Siberia. The larger isl., Big Diomede (Ratmanov), is Russian, while the smaller is part of Alaska. At 2 mi/3.2 km apart, the Diomedes represent the closest approach of U.S. and Russian land masses. Inuit settlement on Little Diomede; Big Diomede is not inhabited.