U.S. Defense Secretary Leon Panetta won't dispute a report that he believes Israel may attack Iran this spring in an attempt to set back the Islamic republic's nuclear program.

Panetta was asked by reporters to comment on a Washington Post opinion column by David Ignatius that said Panetta believes there is a "strong likelihood" that Israel will attack in April, May or June. Ignatius did not say who told him this.

Asked whether he disputes the report, Panetta said, "No, I'm just not commenting."

He added, "What I think and what I view, I consider that to be an area that belongs to me and nobody else."

He noted that Israel has stated publicly that it is considering military action against Iran. He said the U.S. has "indicated our concerns."

In the Washington Post piece, Ignatius writes, "Israeli Prime Minister Benjamin Netanyahu doesn’t want to leave the fate of Israel dependent on American action, which would be triggered by intelligence that Iran is building a bomb, which it hasn’t done yet."

"Panetta believes there is a strong likelihood that Israel will strike Iran in April, May or June — before Iran enters what Israelis described as a “zone of immunity” to commence building a nuclear bomb," Ignatius writes.

Meanwhile on Thursday, Defense Minister Ehud Barak said that a military operation against Iran must be considered should sanctions on the Islamic Republic do not prove fruitful.

"Today, unlike in the past, there is widespread international belief that it is vital to prevent Iran from becoming 'nuclear' and that no option should be taken off the table," Barak said at the closing day of the Herzliya Conference.