With which country did Nigeria break diplomatic relations in 1963 for exploding a nuclear device in the Sahara?

Nigeria broke diplomatic relations with France in 1963 for exploding a nuclear device in the Sahara. France conducted a series of nuclear tests in the Algerian Sahara between 1960 and 1966, which were strongly opposed by the Algerian government and other African nations, including Nigeria. Nigeria's Prime Minister at the time, Sir Abubakar Tafawa Balewa, condemned the tests as a threat to the security and well-being of the African continent. In protest, Nigeria severed diplomatic relations with France and played an active role in the campaign against nuclear testing in the Sahara. Nigeria's stance, along with the efforts of other African nations, eventually led to the end of French nuclear testing in the Sahara in 1966.