"We are trying to do it before sanctions are imposed at the start of August and then another set of sanctions in November. For the start August it seems a bit short, but we are trying to do it by November," he said.
The European Union's strategy includes a special measure to shield EU companies from US secondary sanctions and a Commission proposal that EU governments make direct money transfers to Iran's central bank to avoid US penalties.
Friday's crucial meeting follows a visit to Europe this week by Iranian President Hassan Rouhani who warned that Iran could reduce its co-operation with the UN nuclear watchdog having already threatened Trump of the "consequences" of fresh sanctions against Iranian oil sales, including closing the strategic Strait of Hormuz waterway in the Persian Gulf.