JUDY WOODRUFF: Now, more talk of an Israeli strike on Iran to stop or slow down that country's nuclear program, and questions about a U.S. response to any Israeli military action.
Ray Suarez has the story.
RAY SUAREZ: With war talk rising, the supreme leader of Iran rallied his public today in Friday prayer broadcast on state television.
Ayatollah Ali Khamenei warned against any military strikes on Iran's nuclear sites.
AYATOLLAH ALI KHAMENEI, supreme leader of Iran (through translator): The U.S. military threats again us are to their detriment, and a real war will harm them 10 times more.
The more they threaten us, the more harmful it will be for them. They should know and, of course, they know, that, in return for such war threats and oil embargo threats, we have our own threats to make in proper time, if deemed necessary.
RAY SUAREZ: Khamenei also took on Israel again, calling it a cancerous tumor that should be cut and will be cut.
AYATOLLAH ALI KHAMENEI (through translator): We will continue to support every nation, every group that is confronting and fighting the Zionist regime. We will support and help them.
RAY SUAREZ: The rhetoric took on new import after months of growing tensions over Tehran's nuclear program.
The Islamic republic has repeatedly denied its goal is to build nuclear weapons, as Israel and the U.S. claim. Yesterday, Israeli Defense Minister Ehud Barak issued his strongest warning yet that time is running out.
At a security conference in Israel, he said, "Dealing with a nuclear Iran will be more complicated, more dangerous, and more costly in lives and money than stopping it. And whoever says later may find that later is too late."
And Israel's vice premier, Moshe Ya'alon, underscored his government's view that even Iran's underground nuclear sites are vulnerable.
MOSHE YA'ALON, Israeli vice prime minister (through translator): There was a debate in the United States about whether bombs can or cannot penetrate an Iranian underground installation. From my own military experience, any facility that is guarded by a human being can be targeted.
RAY SUAREZ: At almost the same time, a Washington Post column by David Ignatius raised eyebrows. Ignatius wrote that U.S. Defense Secretary Leon Panetta -- quote -- "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."
In Brussels yesterday, at a NATO meeting, Panetta declined to dispute the report. Instead, he said, "No, I'm just not commenting."
Today, in Germany, Panetta said the key is to maintain tough economic sanctions on Iran. But he said all options are on the table, and the U.S. is "prepared to respond if we have to."
Either way, the Iranian supreme leader, Ayatollah Khamenei, insisted Iran remains defiant. As if to underscore that point, Iran took a new step in its space program with the launch of a new satellite this morning. That same missile technology can be used to fire warheads.