Joe Biden was inaugurated as president. The White House Press Secretary remarked that “through follow-on diplomacy, the U.S. seeks to lengthen and strengthen nuclear constraints on Iran and address other issues of concern. Iran must resume compliance with significant nuclear constraints under the deal in order for that to proceed”. The same day, President Rouhani remarked: “They [ie, the new U.S. administration] should know that if they sign UN Resolution 2231, in return, Iran will sign it as well and nothing more, if they issue an order, Iran will issue an order, and if they take action, they will see action from us… The ball is in the court of the U.S.”. “If the other side acts honestly and returns to the law and obligations, the problems will be solved very quickly and there would be no legal complexities”, he added.