The head of Tehran's nuclear program acknowledged on Wednesday that the new UN sanctions imposed on Iran were having an effect but vowed the work would continue, ISNA news agency reported.

"We cannot say the sanctions have not taken effect. They may slow down the work [in the nuclear sector], but in no way will they stop it," ISNA quoted Ali Akbar Salehi as saying.

The UN Security Council approved on June 9 a fourth round of economic sanctions against Iran over its controversial nuclear activities, including tougher financial controls and an expanded arms embargo.

Following the resolution, the United States and the European Union also announced that they were imposing new sanctions on Iran and earlier this month U.S. President Barack Obama signed a law expanding unilateral sanctions against 30 Iranian companies and individuals involved in developing nuclear and missile technology.

MOSCOW, July 7 (RIA Novosti)