This 1977 MEMCON describes a discussion between President Carter and Nigerian Lt. General Olusegun Obasanjo regarding nuclear suppliers:

Nigerian Lt. General Olusegun Obasanjo  What about China?

President Carter: They feel that nuclear power is their own business.
But they are not a major supplier, and they probably don’t wish to be.
They are facing the Soviet atomic threat. China wants an international conference, and wants that to lead to the elimination of nuclear explosives worldwide. But while they’re facing the USSR, they do not wish limitations to be placed on their capacity in this regard.