0150 GMT February 18, 2020
The top Iranian official made the remarks in an interview with NBC News in Tehran on Monday.
"The sanctions campaign is not for negotiation, it's for making us surrender," said Shamkhani. "As long as this approach is taken by the United States, Iran will never ever seek negotiations."
Shamkhani added that he thinks Trump's "maximum pressure" campaign is failing because the US public and Western allies are "questioning" his leadership.
In 2015, after nearly two years of talks, the Barack Obama administration joined China, Russia and the European powers in signing the nuclear deal with Iran, known as the Joint Comprehensive Plan of Action (JCPOA), an agreement in which Iran accepted limits on its nuclear program in return for sanctions relief.
The Trump administration officially withdrew from the deal in 2018 and reimpose sanctions on Tehran as part of its “maximum pressure” campaign aimed at forcing Tehran to renegotiate a new deal that addresses its ballistic missile program and regional influence as well.
"We had a case of successful negotiations with the JCPOA. How come the United States departed from it?"
Shamkhani said the Iranian public has long dealt with international sanctions and proof of the failure of Trump administration policy was obvious in the mood on the street.
"Just walk the streets of Tehran and see how energetic our people are and you will realize that [what the US has] been trying to achieve has not materialized."
The Iranian official also said his country should never have signed the international nuclear deal.
Prime source of tension
Shamkhani also painted the US as the aggressor and prime source of tension in the region and warned the US to "act with wisdom."
In recent months, tensions have been running high between Washington and Tehran after US military buildup in the Persian Gulf on the pretext of deterring Iranian threats and Iran’s downing of a US surveillance drone on June 20 following its violation of Iranian airspace.
Following the incident, Trump claimed that the US air force was “cocked and loaded” to attack three Iranian targets, but he called off the strike with 10 minutes to spare after being told that the airstrike might kill as many as 150 people.
However, Shamkhani said that the Trump's decision not to attack Iran was driven by a "calculation of cost and benefits."
Should the US and Iran become engaged in an open military conflict, Iran has "multiple instruments at hand, Shamkhani said, warning that both the US and its regional allies would be in "a terrible situation" in the event of war.
"There is no doubt that the already tarnished image of the United States will be even further destroyed in the region and the whole world. Why do they basically threaten to launch a war against us?"
Shamkhani underlined that Iran is not a source of terror in the region but a stabilizing force, whose "martyrs" sacrificed their lives and defeated terrorist groups like Al-Qaeda and Daesh.