TEHRAN (Press Shia) – If the US backs out of the 2015 nuclear deal between Tehran and world powers, "no one will trust America again," Iran's president, Hassan Rouhani, told NBC News.

The move would also leave Iran free to resume work on expanding its nuclear capabilities, Rouhani said in the interview, which took place shortly before Trump's first speech to the United Nations General Assembly Tuesday.

Trump told the United Nations General Assembly earlier Tuesday that the nuclear agreement, dubbed as the Joint Comprehensive Plan of Action (JCPOA), is an “embarrassment” to the United States.

In reply, Rouhani warned that "the exiting of the United States from such an agreement would carry a high cost, meaning that subsequent to such an action by the United States of America, no one will trust America again."

He added, "Every word was analyzed many times by countries involved before its ratification, so if the United States were to not adhere to the commitments and trample upon this agreement, this will mean that it will carry with it the lack of subsequent trust from countries towards the United States because the greatest capital that any country has is trust and credibility."

Asked if Iran would continue to abide by the deal if the United State withdrew, Rouhani said his country's commitments "would no longer exist" and it would be free to pursue a new path.

"One of the options and choices were one of our counterparts not to remain in the current framework would be to go back to previous activities," Rouhani said. "This is one option. And that's not difficult. We can easily go back to previous conditions if counterparts were to not live up to their commitments. But you do know fairly well that Iran will not be the initiator of this return to that path."

But he stressed that Iran would resume "peace activities only," saying the country had no intention of leaving the agreement.

"So we will never go towards production of nuclear weapons, just as in the past we never intended to go towards that path nor did we ever. It has always been peaceful."

"We wish to have nuclear energy for peaceful uses just as today, in Arak, there is collaboration between America, China and Iran for the completion of the power plant in Arak," Rouhani said of the industrial city where his country has been modifying a reactor pursuant to the nuclear agreement.

Iran and the Group 5+1 (Russia, China, the US, Britain, France and Germany) reached the 159-page nuclear agreement in July 2015 and started to implement it in January 2016.

Since the historic deal was signed in Vienna, the IAEA has repeatedly confirmed the Islamic Republic’s compliance with its commitments under the JCPOA, but some other parties, especially the US, have failed to live up to their undertakings.

The US has even imposed many fresh sanctions against Iran, in flagrant defiance of the JCPOA.