Ali Akbar Salehi

A senior Iranian official has acknowledged for the first time that sanctions against the country could slow down its nuclear program.

Ali Akbar Salehi, the head of Iran’s atomic energy agency, told the ISNA news agency on Wednesday that the sanctions could have some impact.

“Maybe they will slow down the work but they will not stop it, that’s certain,” Salehi said.

Mahmoud Ahmadinejad, the Iranian president, previously said that a new wave of sanctions imposed by the United Nations, the U.S. and the European Union would have no impact on Iran’s economy or its nuclear program.

He called the U.S. sanctions “pathetic” and said that the UN resolution was worth no more than a “used handkerchief.”

Barack Obama, the U.S. president, had signed into law earlier this month far-reaching U.S. sanctions aimed at squeezing Iran’s refined petroleum imports.

The UN sanctions adopted in June, among other measures, expanded an arms embargo against Tehran and called for new measures against Iranian banks with suspected connections to the country’s nuclear or missile programs.