United Nations chief Ban Ki-moon and Iran's supreme leader, Ayatollah Ali Khamenei, sparred in an unusually frank verbal duel Wednesday over Tehran's disputed nuclear program, betraying high tensions on the issue.
Mr. Ban told Ayatollah Khamenei and, separately, President Mahmoud Ahmadinejad to take "concrete" steps to fix the worsening international showdown over their atomic activities, according to his spokesman.
But Ayatollah Khamenei, according to his official website, shot back by saying the "defective" UN was in thrall to the United States, and accusing the UN nuclear watchdog of "sabotaging" Iran's nuclear progress.
The tough-talking exchange came on the eve of a two-day summit in Tehran of the Non-Aligned Movement, at which Mr. Ban is a star guest. Iran's leaders had portrayed the event as proof that they were not as isolated as the West was saying.
Mr. Ban also took Iran's leaders to task over their recent descriptions of Israel as a "cancerous tumour" that should be excised and Mr. Ahmadinejad's Holocaust-denying remarks. He told the Iranian leader he "strongly objected" to those words, and said "such offensive and inflammatory statements were unacceptable and should be condemned by all," his spokesman, Martin Nesirky, told reporters.
The two also discussed the role Iran could play in quelling the violence raging in Syria, whose regime it staunchly supports.