VIENNA (Reuters) - Iran wants European powers to give it a package of economic measures by the end of the month to compensate for the U.S. withdrawal from their 2015 nuclear agreement with world powers, a senior Iranian official said on Friday.

“We expect the package to be given to us by the end of May,” the official told reporters before talks in Vienna with Britain, China, France, Germany and Russia.

He added that Tehran would decide within the next few weeks whether to stay in the accord.

The nations that remain in the Iran nuclear deal meet later today for the first time since U.S. President Donald Trump left the pact, but diplomats see limited scope for salvaging it after Washington vowed to be tougher than ever on Tehran.

The U.N. atomic watchdog policing the nuclear accord said on Thursday that Iran is still complying with the terms of the deal despite the U.S. withdrawal, but that it could be faster and more proactive in allowing snap inspections.

The official said that if they were unhappy with how things panned out they would seek a ministerial meeting and then decide.

“I am personally maybe not optimistic but ... I am trying my best to come to a conclusion,” he said.

He said European measures would need in large part to ensure that oil exports remained the same and that the SWIFT international payments messaging system continued to work for Iran.