As widespread fraud in the Afghanistan presidential election was becoming clear three months ago, the No. 2 United Nations official in the country, the American Peter W. Galbraith, proposed enlisting the White House in a plan to replace the Afghan president, Hamid Karzai, according to two senior United Nations officials.

Mr. Karzai, the officials said, became incensed when he learned of the plan and was told it had been put forth by Mr. Galbraith, who had been installed in his position with the strong backing of Richard C. Holbrooke, the top American envoy to Afghanistan. Mr. Holbrooke had himself clashed with the Afghan president over the election.

Mr. Galbraith abruptly left the country in early September and was fired weeks later. Mr. Galbraith has said that he believes that he was forced out because he was feuding with his boss, the Norwegian Kai Eide, the top United Nations official in Kabul, over how to respond to what he termed wholesale fraud in the Afghan presidential election. He accused Mr. Eide of concealing the degree of fraud benefiting Mr. Karzai.

Mr. Galbraith said in an interview that he discussed but never actively promoted the idea of persuading Mr. Karzai to leave office.