This week's warnings from US President George W. Bush and Adm. Mike Mullen, the chairman of America's Joint Chiefs of Staff, against an IDF strike on Iran are a sign that Washington is concerned that Jerusalem may indeed attack the Islamic Republic, Israeli government officials said Thursday. Also on Thursday, Channel 2 analyst Ehud Ya'ari reported that Iran had expressed readiness to freeze its uranium enrichment program in return for the lifting of the international sanctions imposed on it. Citing unnamed Western officials, he said the Iranians had conveyed messages indicating they could accept the latest incentive package offered by the West in return for halting its enrichment program. Meanwhile, a State Department spokesman said the US was sticking to its demand that Iran halt uranium enrichment as a precondition for US participation in negotiations with the Islamic republic over its nuclear program. He added, however, that the US would not rule out early consultations with Iran before official talks begin on resolving its standoff with the West. The spokesman went on to say that Washington would not dismiss the option of Iran stopping enrichment for a limited time in exchange for the removal of sanctions. However, he stressed that Teheran must first give a detailed response to the EU incentive package, Israel Radio reported. The Jerusalem Post could not confirm the report. Mullen said late Wednesday that an Israeli attack on Iranian nuclear facilities would be a high-risk move that could destabilize the Middle East. At a Defense Department news conference, he refused to say what Israeli leaders had told him during meetings last week about any intentions to strike Iran. Asked whether he was concerned Israel would strike before the end of the year, Mullen said: "This is a very unstable part of the world and I don't need it to be more unstable." Israeli officials said the fact that Mullen gave a press conference on the matter indicated he was not reassured by what he heard on his visit to Israel. One of the purposes of his visit was to see whether recent comments made here, such as those made by Transportation Minister Shaul Mofaz, who said Israel might have no choice but to act against the Islamic Republic, were "just words" or indicated real intent. Israel's large air force exercise over the eastern Mediterranean in the first week of June, which was widely described as a "dress rehearsal" for an attack on Iran, has also caused concern in Washington, the officials said. Mullen's visit was his second in seven months. Prior to December, the chairman of the Joint Chiefs had not been in Israel in more than 10 years. He said Thursday that opening a third front now, with the US military already stretched thin by wars in Iraq and Afghanistan, "would be extremely stressful on us." "I believe they're [the Iranians] still on a path to get nuclear weapons and I think that's something that needs to be deterred," and that this should be done through diplomatic, financial and economic actions by the US and other nations, Mullen said. But, he added, "I think that just about every move in that part of the world is a high-risk move." In a news conference earlier in the day, President Bush was also asked about increasing speculation that Israel will launch a strike, and said that all options are on the table but that military action would not be his first choice. "I have made it very clear to all parties that the first option ought to be solving this problem diplomatically," Bush said. "And the best way to solve it diplomatically is for the United States to work with other nations to send a focused message - and that is: You will be isolated, and you will have economic hardship, if you continue to enrich" uranium for a bomb. Israeli officials said Iran was also the main topic of conversation when Bush called Prime Minister Ehud Olmert on Wednesday to express his condolences for the victims of the bulldozer attack in Jerusalem. "All this is designed to throw cold water on any possible Israeli intentions," the officials said. "They are worried by the atmosphere in Israel, and that reports of an inevitable attack have suddenly started to dominate the debate."