Ghana was suspected of casting the single early vote opposing former South Korean Foreign Minister Ban Ki-moon's election as U.N. secretary-general, according to a former U.S. envoy to the United Nations.

John Bolton recounts in his new book, "Surrender Is Not an Option," the process leading up to Ban's eventual election to the top U.N. post.

Ban had suspected Ghana of voting against him after Japan's envoy, Kenzo Oshima flatly denied casting the disapproval vote, according to the book.

However, Bolton said he personally suspected that the "discourage" vote against Ban had come from Japan and persuaded Oshima to change his government's mind.

Bolton said when he met with Oshima and urged him to reconsider Japan's "discourage" vote, he did not deny it.