In 1955, President Dwight Eisenhower nominated Cooper as U.S. Ambassador to India and Nepal. During his time as a delegate for the United Nations, Cooper had met Indian Prime Minister Jawaharlal Nehru and established a cordial working relationship with the Indian delegation, including Nehru's sister Vijaya Lakshmi Pandit. The Indians had been impressed with Cooper and the Indian government had expressed their desire that Cooper serve as their ambassador from the U.S. Cooper initially rejected the offer of the Indian ambassadorship from Secretary of State John Foster Dulles but was convinced to accept it by a personal request from President Eisenhower. The Senate confirmed Cooper's nomination on February 4, 1955.