https://www.nbcnews.com/news/world/...e-should-never-have-signed-obama-era-n1043971 Exclusive: Inside Iran as top officials talk about the growing showdown with the U.S. TEHRAN — A top Iranian official and close adviser to Iran's supreme leader says his country should never have signed the international nuclear deal that has now been renounced by President Donald Trump. In an interview with Lester Holt of NBC News, the official, Ali Shamkhani, who rarely speaks to the Western press, said that there were people in Iran who felt that signing the 2015 nuclear pact, known as the JCPOA, was a mistake. Asked by Holt if he was one of those people, Shamkhani said, "Yes. … I'm just following the viewpoints of my nation, the people of Iran." Shamkhani is the military adviser to Supreme Leader Ayatollah Ali Khamenei, and since 2013, has also been the secretary of the Supreme National Security Council, making him Iran's top national security official. A former anti-Shah militant and Revolutionary Guard who once commanded Iran's naval forces, he previously served as minister of defense and mounted an unsuccessful campaign for Iran's presidency in 2001. Ali Shamkhani to NBC News: The cost of war 'would be bigger than the benefits' Aug. 20, 201906:02 In his interview with Holt, who is anchoring "NBC Nightly News" from Tehran on Monday, Shamkhani painted the U.S. as the aggressor and prime source of tension in the region and warned the U.S. to "act with wisdom." He said the Trump administration's "maximum pressure" campaign against Iran would not bring Iran to heel or bring it back to the nuclear negotiating table. "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." In 2015, after nearly two years of talks, the Obama administration joined China, Russia and the European powers in signing the JCPOA deal with Iran, an agreement in which Iran accepted limits on its nuclear program. The Trump administration officially withdrew from the deal in 2018. Said Shamkhani: "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 U.S. has] been trying to achieve has not materialized." According to Shamkhani, 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 ISIS. He did not explicitly deny that Iranian played a role in sabotaging oil tankers in the Strait of Hormuz in recent months, but emphasized Iran's role as a guarantor of security in the region. Exclusive access inside Iran: Is the maximum pressure campaign by the U.S. working? Aug. 19, 201903:27 He denied Iran is seeking nuclear weapons, since he said they are forbidden under Islam and have not provided security to those who have them, like Israel. He also denied that he had a "military wish" for Israel's destruction, saying the Palestinian people would decide Israel's fate. "I believe that the one that is seeking the destruction of Israel is the country that does not see the realities on the ground," said Shamkhani, taking a swipe at the Trump team's Israel policies and Trump adviser Jared Kushner's Middle East peace initiative. "They declare al Quds, or Jerusalem, as the capital of Israel. They pursue the 'Deal of the Century' project." To the Iranians, said Shamkhani, Trump seems to want the same things as all his predecessors as U.S. president, which is to diminish Iran's influence. But Trump, said Shamkhani, managed to forfeit the "achievement " of "neutralizing Iranian nuclear technology" by gutting the JCPOA. Iran, said Shamkhani, is not basing its decisions on U.S. policy on who is president, or on the possibility that Trump will not serve a second term. But he said that he thinks Trump's "maximum pressure" campaign is failing because the U.S. public and Western allies are "questioning" his leadership. Iran releases dramatic video of seized British oil tanker July 20, 201901:38 Trump's recent decision not to attack Iran after the downing of a U.S. drone, said Shamkhani, was driven by a "calculation of cost and benefits." Should the U.S. and Iran become engaged in an open military conflict, Shamkhani told Holt, Iran has "multiple instruments at hand, including the proxy war," but he did not specify who those proxies might be. Iran is a long-time supporter of Hezbollah, Hamas and Yemen's Houthi rebels. Both the U.S. and its regional allies would be in "a terrible situation" in the event of war, said Shamkhani. "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?"