By Barbara Starr
U.S. Defense Secretary Leon Panetta has come to the conclusion there is a growing likelihood Israel could attack Iran sometime this spring in an effort to destroy its suspected nuclear weapons program, according to a senior administration official.
The official declined to be identified due to the sensitive nature of the information.
Panetta's views were first reported by the Washington Post's David Ignatius, who wrote Panetta "believes there is 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."
Asked by reporters in Brussels, where Panetta is attending NATO meetings, the defense secretary refused to comment. But Panetta told reporters the U.S. has "indicated our concerns" to Israel, according to a transcript provided by the Defense Department.
But the official also noted that Israel goes through cycles of making aggressive statements about its intentions toward Iran in an effort to pressure the United States and the West to take more action.
Iran's supreme leader issued a blunt warning Friday that war would be detrimental to the United States - and that Iran is ready to help anyone who confronts "cancerous" Israel.
"You see every now and then in this way they say that all options are on the table. That means even the option of war," Ayatollah Ali Khamenei said during Friday prayers in Tehran. "This is how they make these threats against us.
Israeli Defense Minister Ehud Barak warned Thursday that Iran may be close to the point "which may render any physical strike as impractical," according to Reuters.
But just a few weeks ago, Barak suggested things were not as urgent, saying an Israeli decision on whether to strike Iran's nuclear program was "very far off."
A "confluence' of intelligence has led Panetta to this conclusion, the official told CNN, but declined to offer any specifics except noting that the United States conducts intelligence operations aimed at Israel as it does with many other allies.
The senior administration official also noted that there is a general understanding in the administration that Israel may have come to the firm conclusion Iran is developing a nuclear weapon. Just last week, the recently retired chief of Israeli military intelligence told CNN's David McKenzie that the "Iranians have already decided that they want nuclear weapons," he said. But he added they haven't decided fully to go through with creating the weapons.
The official U.S. assessment is that Iran has not yet made that decision, the source said.
At a Senate hearing on Tuesday, Central Intelligence Agency Director David Petraeus, who said he has regular discussions with Israel's leadership and intelligence head, noted that "Israel does see this possibility as an existential threat to their country, and I think that it is very important to keep that perspective in mind."
At the same hearing, Director of National Intelligence James Clapper noted the United States works closely with the Israelis and said the notion that Israel could strike is "a very sensitive issue right now."
"This is an area that we are very, very concerned about," Clapper said.
Panetta's press secretary, George Little, declined to comment on the report. Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, recently said it would be premature for the United States to consider striking Iran.