"The American view is that following these discussions on Monday and perhaps some others early next week, we should move this to the Security Council and draft a (sanctions) resolution," US Undersecretary of State Burns told reporters on Friday in Berlin. He hoped that a draft resolution would be ready for the opening of the UN General Assembly in the middle of September.

Burns' comments came a day after meeting with representatives from Germany, Britain, France, China and Russia in the German capital on Thursday. He made it clear that Washington is seeking quick UN sanctions against Iran for failing to halt uranium enrichment by August 31. Penalties should include trade restrictions, freezing of personal and corporate assets and visa bans for officials, diplomats and scientists.

But at the meeting no agreement was reached with other Security Council member states. Although there was consensus that "next steps" should be discussed at the next meeting of the Council in September, the US failed to gather conclusive support for sanctions. "This is a complex issue," said Burns on Friday. "We obviously need more time, so we decided to meet again on Monday by conference call."

In particular China and Russia, both veto-holders on the Council, have expressed unwillingness to introduce sanctions, by questioning their effectiveness. Both have expressed doubts about whether Iran represents a real security threat. France meanwhile proposes that world powers be prepared to negotiate with Iran, without Tehran first freezing uranium enrichment.