In a highly unusual rebuff to a close ally as tensions escalated over how to deal with Iran's nuclear program, the White House said on Tuesday, Sept 11, President Barack Obama will not meet Benjamin Netanyahu during the Israeli prime minister's U.S. visit later this month, Reuters reported.

The apparent snub, coupled with Netanyahu's sharpened demands for a tougher U.S. line against Iran, threatened to plunge U.S.-Israeli relations into crisis and add pressure on Obama in the final stretch of a tight presidential election campaign.

An Israeli official, who declined to be identified, said the White House had refused Netanyahu's request to meet Obama when the Israeli leader visits the United States to attend the U.N. General Assembly, telling the Israelis, "The president's schedule will not permit that."

White House spokesman Tommy Vietor denied that Netanyahu had ever made such an overture - let alone that it had been spurned - insisting instead that the two leaders were attending the General Assembly on different days and would not be in New York at the same time.