US sees window for Iran nuclear talks closing

The window for dialogue over Iran\'s nuclear programme is closing, the US ambassador to Israel said Wednesday, insisting Washington holds no illusions over Tehran\'s agenda at the talks. Speaking at Tel Aviv University a week after world powers held a second round of largely fruitless talks with Iran, ambassador Dan Shapiro insisted Washington would not continue such dialogue forever. \"We don\'t intend on continuing talks for talks\' sake. The window is closing,\" he told delegates attending an international security conference at the university. \"We have no illusions that Iran may be using this to buy time,\" he said. \"It is up to Iran to follow through. The burden falls on Iran to prove it is serious.\" Iran and the P5+1 -- the United States, Russia, China, Britain, France and Germany -- achieved little in two days of intense talks in Baghdad last week except for setting up another meeting in Moscow in June. Shapiro said there were \"significant differences\" at the Baghdad talks, but also \"a narrow common ground\" which the parties would try to build on in the Russian capital. But the US envoy warned the \"harshest sanctions\" were yet to come. And he said the threat of military action against Iran\'s nuclear facilities was still open. \"As we apply all elements of American power to prevent a nuclear Iran, the United States takes no option off the table -- that means a political component, a diplomatic component, an economic component and a military option,\" he said. Neither Washington nor Israel has ruled out the option of a military strike but the Obama administration has made clear it favours diplomacy over force at this stage. Shapiro said Washington and Israel both agreed that Iran should stop all enrichment, not just enrichment to a high level. \"Exactly like Israel, the United States believes Iran must cease all uranium enrichment,\" he said, insisting on the necessity for Tehran to \"take concrete measures\" to prove it was doing so.