Iranian President Hassan Rouhani told President Trump not to impose sanctions on the regime, warning the Iranians could restart their nuclear program "within hours" in retaliation.

"If they are inclined to get back to those experiences, Iran would certainly return in a short time -- not a week or a month but within hours -- to a situation more advanced than before the start of negotiations," Rouhani told Iranian parliament, per a semi-official domestic media outlet.

That threat likely will be tested as Trump implements a new sanctions law recently passed by Congress in response to Iranian aggression beyond the nuclear weapons program. Rouhani accused the United States of breaking the nuclear pact and portrayed Trump as an unreliable and belligerent leader.

"The world has clearly seen that under Trump, America has ignored international agreements [negotiated by former President Barack Obama's administration] and ... has shown to the world and even its allies that the United States is no good partner or reliable negotiator," Rouhani said.

Secretary of State Rex Tillerson's team maintained that "we are complying" with the deal by providing the sanctions relief required under the terms of nuclear pact, known as the Joint Comprehensive Plan of Action.

"But we still believe that what Iran is doing is destabilizing and that the JCPOA doesn't fully recognize and comprehend and encompass all those destabilizing activities that Iran is engaged in," State Department spokeswoman Heather Nauert said Tuesday.

Iran hawks argued Rouhani's threat shouldn't be taken seriously.

"Rouhani has staked significant political capital to ink the 2015 nuclear deal, and more importantly, he rightly understands how much the accord provides Iran," Behnam Ben Taleblu, an analyst at the Foundation for Defense of Democracies, told the Wall Street Journal.

The National Iranian-American Council, which defends the agreement, accused Trump of destabilizing the deal and the region.

"We warned that new congressional sanctions would lead to Iran doubling down on its missile program and the Revolutionary Guard, empowering hardline elements while destabilizing the JCPOA," Trita Parsi, the president of the council, said Tuesday.

But Trump's national security team won't overlook Iranian aggression — increased support for terrorists in Lebanon, for instance, and harassment of U.S. vessels in the Persian Gulf — in order to avoid angering the regime.

"Iran cannot be allowed to use the nuclear deal to hold the world hostage," Nikki Haley, the U.S. ambassador to the United Nations, said in response to Rouhani. "The nuclear deal must not become 'too big to fail.'"

Rouhani, for his part, mocked the United States for using a weapon colloquially known as "the mother-of-all-bombs" in the fight against ISIS in Afghanistan, while declaring that their own programs are not a threat to the world.

"Today is not the time for displaying the mother of all bombs; today is not the time for unveiling mother of sanctions; let's unveil the mother of talks," Rouhani said. "We are after peace. Our weapons are meant for peace and our [quest for] peace relies on our arms."