MOSCOW, August 21. /TASS/. Iran sees it as a top priority in its foreign policy to defend the agreement on the Iranian nuclear deal, Mehr news agency said on Sunday, citing President Hassan Rouhani as saying in an address to the national parliament.

"It is the major duty of [Javad] Zarif and the foreign ministry [for the next four years] to defend Iran’s nuclear deal and not to let the United States and other countries disposed against Iran implement their plans of wrecking the deal," Rouhani said.

After the US administration said on July 18, 2017 it had supplemented the anti-Iranian black list with 18 organizations and individuals supporting Iran’s ballistic missile program, Iranian military purchases and the IRGC (Iran's most powerful security and military organization), Iran filed a complaint with the United Nations Security Council over the United States’ sanctions and accused Washington of violating the nuclear deal.

On August 15, President Rouhani warned that Tehran would withdraw from the deal as soon as the United States imposes further anti-Iranian sanctions. Two days before that, the Iranian parliament voted in favor of allocating an extra sum of 520 million dollars to finance the program of the development of ballistic missiles and expansion of the IRGC (Islamic Revolutionary Guards Corps) presence in the region.

The deal on Iran’s nuclear program was reached between Iran and six international mediators (the United Kingdom, Germany, China, Russia, the United States, and France) on July 14, 2015.

On January 16, 2016, the parties to the deal announced beginning of its implementation. Under the deal, Iran undertakes to curb its nuclear activities and place them under total control of the International Atomic Energy Agency (IAEA) in exchange of abandonment of the sanctions imposed previously by the United Nations Security Council, the European Union and the United States over its nuclear program.