He said that like most people he knew, he had no inclination to rise up against Iran’s leaders. “But if they talk to Trump and things will get better, I think that will be great and many people will be happy,” he said.

In a small shop in West Tehran, where Mohammad Shahdadi, 33, sells plastics and disposable items like cups and buckets, business was slow, as it has been for a while, he admitted. “My question is: Why should we continue our current foreign policy?” he said. “It’s time for change. For the sake of Iranians, to save us from this bad situation, our leaders should sit down with Trump and solve the old disputes between our countries.”

The list of those disputes is long. In 1953, the Central Intelligence Agency organized a coup against the democratically elected prime minister, Mohammad Mossadegh, and Washington strongly backed the authoritarian Shah Mohammed Reza Pahlavi for years.

In 1979, Iranian revolutionary students occupied the American Embassy and took 52 Americans hostage, and after that Washington supported Iraq during its bloody eight-year war with Iran. Over the decades there have been sanctions, cyberattacks and other secret operations, terrorist attacks and various diplomatic disputes. Now, the Trump administration, besides withdrawing from the nuclear deal, is blaming the Iranian leadership for most of the problems in the Middle East and is talking about regime change.

“In reality, direct talks are not realistic under the current conditions,” said Saeed Laylaz, an economist close to the Iranian government. Not only is there a lot of old bad blood, he said, President Trump also has set different conditions for Iran than he did for North Korea. “He wants Iran to give up everything, without offering any incentive in return,” Mr. Laylaz said. “Why should we sit down with him under such conditions?”

Iranian officials are also wary of Mr. Trump’s mercurial nature. A government spokesman, Mohammad Bagher Nobakht, warned North Korea this week that Mr. Trump could not be taken at his word, pointing to his decision to rescind his signature on the communiqué of the Group of 7 meeting in Canada.

“I do not know who the North Korean leader is conferring with,” Mr. Nobakht said. “This man is not a wise representative of America. I hope that the American nation itself will do something about him.”