relations with the United States; US relations
Used in political, diplomatic, and economic contexts to refer to the bilateral relationship between Japan and the United States.
Japan-US relations have been strengthened over many years.
Improving relations with the United States is a future challenge.
日米関係 specifically refers to Japan-US relations, while 対米関係 can refer to any country's relations with the US, though often used for Japan.
Compound of 対 (toward, against) + 米 (America, from 亜米利加) + 関係 (relations).