A senior Palestinian diplomat at the United Nations said on Tuesday that Zahar, a senior leader of the Islamic militant group, had made the reference in a letter he sent to U.N. Secretary-General Kofi Annan this week.

But a Hamas official in Gaza told Reuters the wrong letter had been sent. The official said Zahar made changes to an initial draft of the letter, such as deleting references to the two-state solution. The older version was mistakenly sent.

Earlier, Zahar angrily denied referring to a two-state solution in the letter, dated April 4.

"Such a sentence was not used in the letter," Zahar told Reuters in the Gaza Strip. A version of the letter circulated in Gaza was the updated one.

Hamas, which swept parliamentary elections in January and is sworn to destroy Israel, has vowed to keep fighting the Jewish state since taking over the Palestinian government last week. It says talks with Israel would be a waste of time...