The United States expects Security Council agreement on UN sanctions against Iran within weeks unless Teheran does a last-minute turn and agrees to freeze uranium enrichment, a senior State Department official said Friday. US Undersecretary of State Nicholas Burns additionally dismissed suggestions of cracks in the six-power coalition pushing Teheran to give up enrichment, in comments a day after those countries ended confidential discussion on Iran in the German capital. Burns said further talks were needed on how harshly to penalize Teheran for its refusal to freeze uranium enrichment, as demanded by the Security Council, but a lot of progress was made at those discussions. Outlining the US view of the timetable on Iran in the coming weeks, Burns said the six nations would further consult by phone on Monday and hoped to present a unified approach on sanctions to their foreign ministers by the time the UN General Assembly opens Tuesday. "It's fair to say we have...a lot more work to do," he told guests at an event staged by The American Academy in Berlin. "But I believe we will be successful in passing the sanctions resolution shortly" in the Security Council, he added. Thursday's meeting in Berlin came amid broad moves by key European nations to enlist world support in pressuring Iran to give up uranium enrichment. In a confidential document obtained by The Associated Press and sent to dozens of capitals last week, Britain, France and Germany warned that Teheran's stalling tactics on whether it is ready to meet six-nation terms for new nuclear talks is an attempt "to split the international community." Burns, in comments to reporters Thursday, dismissed suggestions of a split, saying all five permanent Security Council members insist that Iran must first suspend its enrichment activities, and only then can negotiations start.