Iranian officials at the United Nations confirmed the deal to The Associated Press, saying that the prisoner release "marks a significant initial step in the implementation of this agreement."
The U.S. in March called remarks by Iranian Foreign Minister Hossein Amirabdollahian that a deal for a swap was close a "cruel lie." "While this is an encouraging step, these U.S. citizens ... should have never been detained in the first place," she said in a statement. "We will continue to monitor their condition as closely as possible. Of course, we will not rest until they are all back home in the United States."
The alleged violations include the transfer of funds through Venezuela and sales of dual-use equipment that the U.S. alleges could be used in Iran's military and nuclear programs. Iran has been enriching uranium and stockpiling it as part of its advancing nuclear program. Four American captives, including Washington Post journalist Jason Rezaian, flew home from Iran, and several Iranians in the United States won their freedom. That same day, the Obama administration airlifted $400 million in cash to Tehran.