Barak statements on Iran worry West Israeli Defense Minister Ehud Barak speaks at National Harbor in Maryland Dec. 15, 2011. UPI/Alison O'Brien/HO HERZLIYA, Israel, Feb. 3 (UPI) -- U.S. and Western officials expressed concern over the latest statements by an Israeli leader concerning possible airstrikes against Iranian nuclear sites. U.S. officials said they were concerned about the tenor of comments made by Israeli Defense Minister Ehud Barak, who said Thursday the window was closing for ending Iran's nuclear work, fueling concern among Western leaders that a surprise attack by Israel could lead to a broader military conflict in the Middle East, The Washington Post reported. "Whoever says 'later' may find that later is too late," Barak said during a security forum attended by some of Israel's key military and intelligence leaders. Acknowledging the seriousness of the Iranian threat, U.S. officials said they worried about being caught off-guard by an Israeli strike that could have broad economic and security implications and may only delay Iran's nuclear aspirations, not end them. At Thursday's Israeli security conference in Herzliya, Barak and other Israeli officials noted recent moves by Iran to begin enriching uranium at a second plant in a mountainside bunker near Qom. Once the fortified facility is finished, deterring Iran will be far more difficult, they say. Barak, dismissing criticism that Israel failed to fully consider the implications of military action, said: "There is no basis for the claim that this subject ... was not discussed with appropriate breadth and depth. The assessment of many experts around the world, not only here, is that the result of avoiding action will certainly be a nuclear Iran, and dealing with a nuclear Iran will be more complicated, more dangerous and more costly in lives and money than stopping it. In recent weeks, Western officials have urged Israel to be patient. They've said recently imposed economic sanctions and a new European Union oil embargo are hurting Iran's economy and could force the country's leaders to abandon the program the West thinks is for nuclear weapons but Tehran maintains is for peaceful purposes, the Post said. "Israel has indicated they're considering this, and we have indicated our concerns," U.S. Defense Secretary Leon Panetta said Thursday in Brussels, where he was attending a NATO meeting. British Deputy Prime Minister Nick Clegg, in a magazine interview, said he was worried that an Israeli attack on Iranian nuclear facilities would result in a military conflict "and that certain countries might seek to take matters into their own hands." During Friday prayers in Tehran, Ayatollah Seyyed Ali Khamenei said the country would maintain its progress despite pressure from the West, the government-backed Press TV reported. "The advancement of the Islamic Revolution has never stopped as we have been on the right track," Khamenei said.