VIENNA - Major powers and Iran agreed on Friday to move quickly to offset the U.S. pullout from its nuclear deal and Washington's renewed sanctions, with Tehran pressuring Europe to come up with a package of economic measures by May 31.The 2015 agreement between Iran and world powers lifted international sanctions on Tehran. In return, Iran agreed to restrictions on its nuclear activities, increasing the time it would need to produce an atom bomb if it chose to do so.Since President Donald Trump withdrew the United States this month, calling the agreement deeply flawed, European states have been scrambling to ensure Iran gets enough economic benefits to persuade it to stay in the deal.But this has proven difficult, with many European firms alarmed at the specter of far-reaching U.S. financial penalties.Nations that remain in the deal - Britain, China, France, Germany and Russia - held a formal meeting on Friday without the United States for the first time since Trump's announcement, but diplomats saw limited scope for salvaging the agreement."For the time being we are negotiating... to see if they can provide us with a package which can actually give Iran the benefits of sanctions-lifting and then the next step is to find guarantees for that package," Iran's Deputy Foreign Minister Abbas Araqchi told reporters after the meeting.The talks between senior officials aimed at fleshing out the package of measures to keep oil and investments flowing.Those measures include banning EU-based firms from complying with the reimposed U.S. sanctions, urging governments to make transfers to Iran's central bank to avoid fines and creating alternative financing channels."We expect the (economic) package to be given to us by the end of May," a senior Iranian official said earlier, adding that Tehran was "weeks" away from deciding whether to quit the pact.European measures would need to ensure that oil exports did not halt, and that Iran would still have access to the SWIFT international bank payments messaging system, he said.A senior EU official said the participants had stressed on Friday that the package would not be immediate."We made it very clear today that there are things that will take more time," the official said.Foreign ministers of the remaining countries will meet in the coming weeks.