This interview with Ambassador Howard Schaffer describes a 1978 visit to India by President Carter:

The major issue between the U.S. and India at the time concerned
the delivery of fuel to Tarapur, a nuclear reactor. It was the Indian tail wagging the
American dog. On the first day during a break, Carter was huddled with Brzezinski and Cyrus Vance, then the Secretary of State. They were unaware that a microphone near them was open and transmitting their comments. I was in the room and heard Carter say something about sending a cold, hard note to the Indians about the fuel problem. The story subsequently got world headlines.