Zinni, a former commander of Central Command, told The Washington Times he was offered the job by White House national security adviser, retired Marine Gen. James Jones, and Secretary of State Hillary Clinton later confirmed it.
After starting to making arrangements, Zinni said he became concerned because he heard nothing from either the State Department or the White House. When he called Jones, he said he learned veteran diplomat Christopher Hill would be the likely nominee.
A U.S. ambassador to Iraq has not been nominated, and the State Department offered no comment.
Zinni said he never was given a reason why the appointment was withdrawn, which Zinni said bothered him because "I was told that I had it."
"We have spoken to a number of extraordinarily talented individuals about serving in this important role, and have made no announcement about who will be the U.S. ambassador to Iraq," said Tommy Vietor, a White House spokesman. "Obviously, the president has enormous respect for General Zinni, and believes he would be on anybody's short list for a number of critical national security roles."
Zinni indicated that he wasn't interested in another offer from the administration.