New sanctions approved by Congress this month penalized Iran for its ballistic missile program and other activities in the region. Iran says that it has the right to conduct missile tests and that it has fully complied with the provisions of the nuclear agreement.

While Mr. Rouhani was re-elected this year, he has faced increasing pressure from hard-liners, who have said all along that the United States is not to be trusted and will never deliver on its promises. The economic benefits Mr. Rouhani promised from the signing of the nuclear deal have not been completely realized, largely because of unilateral American sanctions that have deterred much foreign investment.

Mr. Trump’s threats to withdraw from the nuclear agreement have added weight to the hard-liners’ arguments, putting Mr. Rouhani ever more on the defensive and weakening him politically. On Monday, for example, conservatives were able to tighten their grip on the Expediency Council, one of Iran’s most influential oversight bodies.

Mr. Rouhani warned the Trump administration that Iran could react quickly if further sanctions were confirmed. “The new U.S. officials should know that the failed experience of sanctions and coercion compelled their previous governments to eventually come to the negotiation table,” Mr. Rouhani said. “If they want to try those experiences again, Iran will definitely revert to a far more advanced situation than it had before the negotiations, not in a matter of weeks or months but in a matter of days or hours,” he told lawmakers.

Mr. Rouhani also noted that Mr. Trump had pulled out of several international treaties or was threatening to do so. “It is the U.S. government, especially the current Trump administration, that is ignoring international treaties,” he said, “showing to the world and its allies that the U.S. is neither a good ally nor a trustworthy negotiating partner.”