The U.N. Security Council on Friday rejected another last-ditch effort to delay the reimposition of sanctions on Iran a day before the deadline after Western countries claimed that weeks of meeting with officials failed to result in a “concrete” agreement.

It comes a day before a series of U.N. “snapback” sanctions are set to take effect as outlined in Iran’s 2015 nuclear deal with world powers.

That would again freeze Iranian assets abroad, halt arms deals with Tehran and penalize any development of Iran’s ballistic missile program, among other measures, further squeezing the country’s reeling economy.

Britain, Germany and France, known as the E3, triggered the so-called “snapback” mechanism last month after accusing Tehran of failing to comply with the conditions of the accord and when weeks of high-level negotiations failed to reach a diplomatic resolution.

Since the 30-day clock began, Iran’s foreign minister, Abbas Araghchi, has been meeting with his French, British and German counterparts to strike a last-minute deal, leading up to this week's U.N. General Assembly gathering.

But those talks appeared futile, with one European diplomat telling the Associated Press on Wednesday that they “did not produce any new developments, any new results.”