The US and Britain have urged Israel not to attack Iran and to give international sanctions against Tehran more time to work.
The warning came as the White House's national security adviser Tom Donilon visits Israel.
The Chairman of the US. joint chiefs of staff, Gen. Martin Dempsey, and British Foreign Minister William Hague said an Israeli attack is "not prudent" and that it would not be "a wise thing."
Speaking to the BBC, he said Britain was focused on pressuring Iran through diplomatic means.
"I don't think a wise thing at this moment is for Israel to launch a military attack on Iran," Hague told the BBC. "I think Israel like everyone else in the world should be giving a real chance to the approach we have adopted on very serious economic sanctions and economic pressure and the readiness to negotiate with Iran."
The US and the European Union have both imposed harsh new sanctions targeting Iran's oil sector.
On Sunday, Iran announced that it has halted oil shipments to Britain and France in an apparent pre-emptive blow against the European Union’s latest sanctions. The EU accounts for about 18 percent of Iran's oil exports.
Israel has welcomed the sanctions but has so far refused to rule out military action and in recent weeks sent signals that its patience is running thin.
Israel considers the Iranian nuclear program as a threat to its very existence, citing Iran's support for Hzebollah and Hamas, its sophisticated arsenal of missiles capable of reaching Israel and Iranian President’s Ahmadinejad’s repeated calls for the destruction of Israel.
Last week, Israel accused Iran of being behind attempted terror attacks on Israeli diplomats in India, Georgia and Thailand.
Gen. Dempsey expressed concern that an Israeli attack could spark reprisals against US targets in the Gulf or Afghanistan, where American forces are based.
Dempsey said he believed that the international sanctions on Iran are beginning to have an effect. "For that reason, I think, that we think the current path we're on is the most prudent path at this point."
Asked whether he believed Israel could be deterred from striking, Dempsey said: "I'm confident that they understand our concerns, that a strike at this time would be destabilizing and wouldn't achieve their long-term objectives. But, I mean, I also understand that Israel has national interests that are unique to them."
US National Security Adviser Tom Donilon met with Israeli Prime Minister Benjamin Netanyahu in Jerusalem but neither the Prime Minister’s Office nor the US put out a statement after that two-hour meeting, and Netanyahu said nothing about it – or the Iranian nuclear program – at a speech immediately after the meeting at the opening of the annual Conference of Presidents of Major American Jewish Organizations in Jerusalem.
Donilon was also scheduled to meet Israel Defense Minister Ehud Barak on Monday before traveling back to Washington.
His visit takes place just two weeks before Netanyahu is scheduled to travel to the US to attend AIPAC’S annual policy conference, and for an expected meeting with US President Barack Obama.
The US and the EU expressed cautious optimism on Friday over prospects that Iran may be willing to engage in new talks. US Secretary of State Hillary Clinton and EU foreign policy chief Catherine Ashton said Iran’s letter to Ashton last week might mark a step forward.