Iran in a complaint to the United Nations has accused the United States of violating its nuclear agreement with world powers by imposing new sanctions over Tehran's ballistic missile testing and rights abuses, Iranian news agencies reported on August 1.
The United States did not immediately respond to Iran's complaint, but U.S. Secretary of State Rex Tillerson said in a news conference on August 1 that he is a strong backer of the nuclear deal and has had to defend it in discussions with President Donald Trump, who has repeatedly said he would like to ditch the deal.
Iran's complaint came after the U.S. Treasury last month imposed sanctions on six Iranian firms for their role in developing ballistic missiles after Tehran launched a rocket capable of putting a satellite into orbit.
The U.S. Congress last month also enacted legislation imposing new sanctions on Iran targeting the missile program, rights abuses and the Islamic Revoluationary Guard Corps.
Ali Larijani, the speaker of Iran's parliament, on August 1 said the new sanctions violate the 2015 nuclear agreement and Iran has taken its case to a UN commission charged with monitoring compliance with the deal, Iran's Tasnim news agency reported.
Iran has previously accused the United States of defying the spirit of the nuclear deal by imposing sanctions, but has not previously taken any formal action against Washington.
The United States, in imposing the sanctions, has maintained that Iran's missile tests violate the "spirit" of the deal and the UN resolution carrying it out, which calls on Iran to refrain from testing missiles that have the capability to carry nuclear weapons.
Tillerson repeated that position on August 1, saying Iran is violating the spirit of the deal because it calls on Tehran to stop ballistic missile tests and be a "good neighbor" to other nations in the Persian Gulf region.
The central trade-off of the nuclear agreement is the lifting of international sanctions against Iran in exchange for curbs on its nuclear activities. But the United States has maintained non-nuclear sanctions against Iran targeting missile development and other activities.
Tillerson said that he has argued within the Trump administration that the nuclear deal can be used to help rein in Iran's other activities in the Middle East which Trump opposes, including its backing of the Syrian government in a six-year civil war, its support for Lebanon's Hizballah, and its backing of Huthi rebels in Yemen.
"There are a lot of alternative means with which we use the agreement to advance our policies and the relationship with Iran, and that's what the conversation generally is around with the president," Tillerson said.
"The greatest pressure we can put to bear on Iran to change their behavior is a collective pressure" made possible by the agreement, he said.
Still, Tillerson acknowledged that he is not sure he has convinced Trump to stick with the deal in the long run.
"He and I have differences," he said. Trump could still "tear it up and walk away," or he could opt to stay in the deal and hold Iran accountable to its terms.
Based on reporting by AP and Reuters