The Trump administration previously stated that while Iran has met the requirements of the nuclear deal, it is breaching its spirit by supporting global terrorism and destabilizing the Middle East.
Iran's Supreme Leader Ayatollah Ali Khamenei condemned what he termed "Washington's disloyalty to the 2015 nuclear deal", warning that "any wrong move" by the United States will be followed by Tehran's "tough reaction".
"They (the US administration) have shown wickedness and malicious behavior with regard to the JCPOA (nuclear deal)", said Khamenei.
"Today, despite all the commitments and discussions in the negotiations, America's attitude towards these negotiations and their outcome is completely unjust and amounts to bullying", Khamenei said.
"The nation of Iran is standing firm and any wrong move... will face a reaction by the Islamic republic", said Khamenei.
Washington last week extended some sanctions relief that was granted under the 2015 nuclear deal between Tehran and world powers under which Iran has significantly limited its controversial nuclear activities in exchange for sanctions relief.
The Iranian leader threatened a harsh response to any attempt by the United States to alter the nuclear deal.
President Hassan Rohani left on September 17 for the UN General Assembly in NY, where he is expected to hold talks on the nuclear deal.
"We expect the European Union to fully implement the nuclear deal, known as JCPOA, and press the United States to be committed to its obligations to the deal, Rouhani said". The Iranian nation stands strong.
Iran is determined to use the post-JCPOA atmosphere and expand relations with European countries, especially Belgium, he added. He may have also been reacting to later news regarding an upcoming meeting between Trump and Prime Minister Netanyahu on a plan to demand that Iran amend the deal to allow inspection of its centrifuges.
The worldwide agreement is facing a serious threat of collapse as tensions mounted between Washington and Tehran recently.