Vice President Joe Biden's statement that Israel can decide on its own whether to strike Iran's nuclear sites should not be construed as an American "green light" for such an action, the State Department said on Monday.

"We are certainly not going to give a green light to any kind of military strike, but Israel is a sovereign country and we're not going to dictate its actions," State Department spokesperson Ian Kelly said on Monday.

"We share the Israelis' deep concerns about Iran's nuclear program," Kelly said. "But you have to ask Israel if they are going to make a strike."

Foreign Minister Avigdor Lieberman on Monday welcomed Biden's statement, calling it "logical."

But other Israeli leaders avoided comment, a low-key reaction that suggested Israel did not see Biden's comments as a green light to strike Iran. President Barack Obama underlined that diplomacy with Iran remains an option.

Israel considers Iran a strategic threat because of its nuclear program and long-range missile development, dismissing Iranian denials that it intends to build nuclear weapons. Israel has been nervous over the Obama administration's attempts to engage Iran, and Israel has pointedly sent clear signals of its military capabilities while urging world action to rein in Tehran.

Meanwhile, the U.S. goal of dialogue with Tehran has been rattled by Iran's heavy crackdown on protesters in the country's disputed presidential election, though Washington says it still hopes the policy will bear fruit.

Interviewed by ABC-TV on Sunday, Biden appeared to depart from his previous comment that an Israeli attack on Iran would be "ill-advised."

Asked about the possibility of an Israeli attack against Iran's nuclear facilities, Biden replied Sunday, "Israel can determine for itself - it's a sovereign nation - what's in their interest and what they decide to do relative to Iran and anyone else."

The White House said Biden's remarks did not signal a shift in U.S. policy. In an interview published by the New York Times on Monday, Obama indicated the diplomatic option was still viable. "We have offered a pathway for Iran to rejoining the international community," he was quoted as saying.

Lieberman's response to Biden's comments was relatively measured. "I think he said things that are very logical," he said. "Israel is a sovereign state and at the end of the day, the government of Israel has sole responsibility for its security and future, not anybody else."

"Sometimes there are disputes between friends, but at the end of the day the decision is ours," he said.

Israeli Prime Minister Benjamin Netanyahu's office has refused to comment, underlining Israel's sensitive position on Iran and on U.S. policy toward Tehran.

Israel, which is widely believed to have a nuclear arsenal of its own, says it would likely be targeted by Iran, based on repeated statements by Iranian President Mahmoud Ahmadinejad referring to Israel's destruction.

But even Israeli hawks like Lieberman recognize the limitations of an Israeli strike. Israel destroyed Iraq's nuclear reactor in a 1981 air strike, but experts do not believe Israel can do the same with Iran's nuclear operations, which are spread around the country, some of them hidden and heavily fortified.

Israel would also have to take into account the desires of the U.S., Israel's most important political and military ally.

The top U.S. military officer, Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, warned Sunday of the danger of an Iranian nuclear weapon - and of the fallout from an attack against Iran.

"I worry about it being very destabilizing not just in and of itself but the unintended consequences of a strike like that," he told CBS TV.

Netanyahu has been warning about the dangers of the Iranian nuclear program for years, calling for intensive world action to stop it. Israeli Defense Minister Ehud Barak, leader of the dovish Labor Party, speaks frequently of leaving all of Israel's options open.

Israel has sent several military signals to Iran.

This week an Israeli submarine said by foreign experts to have the capability of carrying nuclear-tipped missiles returned to the Mediterranean after crossing to the Red Sea in the direction of Iran, a mission seen as a warning. Also, Israel has held air force maneuvers that were described unofficially as practicing an attack on Iranian targets.

Lieberman, who has advocated radical military responses to a range of challenges over the years, could be expected to beat the drum for an Israeli attack on Iran.

Instead, he has voiced a contrasting concern - that Israel might be expected to do the world's dirty work by hitting Iran, leaving the world community free to criticize Israel afterward, as happened after the attack on Iraq in 1981.

During a visit to Russia, Lieberman said, "We do not intend to bomb Iran, and nobody will solve their problems with our hands."