A senior Iranian diplomat has expressed doubts Europe would succeed in salvaging the 2015 nuclear deal between Tehran and world powers.

Axar.az reports that Deputy Foreign Minister Abbas Araghchi's remarks come after days of intense efforts by Tehran to convince European nations to help Iran sell its oil abroad.

U.S. sanctions imposed after President Donald Trump withdrew America from the deal have curbed Iran's oil exports and sent its economy into freefall as what was left of the deal steadily unraveled.

Araghchi said: "it is unlikely European countries can take an effective step" before a weekend deadline by Iran.

He says Europe needs to compensate Iran in the "amount of $15 billion over a 4-month span" and "after that, Iran is ready for talks."