JERUSALEM — Defense Secretary Leon E. Panetta on Wednesday aimed to reassure Israelis that the U.S. is resolved to prevent Iran's leaders from gaining nuclear arms.
"If they proceed with a nuclear weapon, we have options that we are prepared to implement to ensure that that does not happen," Mr. Panetta told reporters here during a brief visit.
Asked if that includes a military strike, he said: "We obviously continue to work on a number of options in that area. ... We will not allow Iran to develop a nuclear weapon. Period."
The defense secretary's comments and his visit come amid rising concern in Washington and among Western nations that Israel will attack Iran's nuclear facilities this year.
Mr. Panetta urged Israeli officials to allow international sanctions more time to weaken Iran's economy and change its leaders' behavior.
But Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak largely downplayed his advice, both saying that time is running out for a diplomatic resolution.
Meanwhile, the Israeli newspaper Yediot Achronot reported this week that nearly all of Israel's security chiefs oppose a preemptive strike against Iran at this time.
Asked about the report Tuesday during a television interview, Mr. Netanyahu declined to comment on its accuracy but stressed that the government that makes such decisions, not the defense establishment. He noted that Prime Minister Menahem Begin ordered the air force to bomb Iraq's nuclear reactor in 1981 against the recommendation of Israel's intelligence community.
"Iran wants to annihilate us. I won't let that happen," he said, adding that he has not yet made up his mind about a preemptive strike.
Mr. Netanyahu and Mr. Barak are widely believed to be the two main advocates of an attack on Iran, which Israel considers an existential threat because of the Islamic republic's calls for the Jewish state's destruction and support for anti-Israel militants such as Hamas and Hezbollah. Iran repeatedly has said its nuclear program has only peaceful aims.
In greeting Mr. Panetta Wednesday at Israeli defense headquarters, Mr. Barak said: "The defense ties between Israel and the United States are stronger and tighter than they have ever been, and the credit now has to go, most of it, to you, Leon."
Mr. Panetta responded: "We are a friend, we are a partner, we have, as the defense minister has pointed out, probably the strongest U.S.-Israel defense relationship that we have had in history. What we are doing, working together, is an indication not only of our friendship but of our alliance to work together to try to preserve peace in the future."
Earlier Wednesday, Mr. Panetta visited a battery of an anti-rocket defense system near the southern city of Ashkelon. The Israeli-devised Iron Dome system, partially funded by the U.S., has proven highly successful in intercepting rockets fired from the Gaza Strip.
Last week, President Obama reaffirmed an earlier pledge to provide Israel with an additional $70 million for more batteries needed to defend the Tel Aviv area.
Mr. Panetta's visit comes just days after U.S. presidential candidate Mitt Romney met with Israeli officials about Iran and other issues. Mr. Romney, a Republican, said he would "honor" Israel's decision about Iran if he's elected. He has accused Mr. Obama of showing weakness on Iran and in supporting Israel.
• This article is based in part on wire service reports.