President Trump announced Friday he will decertify the 2015 Iran nuclear deal, saying he believes the “radical regime” has committed multiple violations of the agreement as he kicked a decision over whether to restore sanctions back to Congress.

“I am announcing today that we cannot and will not make this certification,” Trump said during a speech at the White House. “We will not continue down a path whose predictable conclusion is more violence, more terror, and the very real threat of Iran's nuclear breakthrough.”

Friday's announcement does not withdraw the United States from the Iran deal, which the president called “one of the worst and most one-sided transactions the United States has ever entered into.”

But the president threatened that he could still ultimately pull out of the deal.

“In the event we are not able to reach a solution working with Congress and our allies, the agreement will be terminated,” he said. “It is under continuous review and our participation can be canceled by me as president at any time.”

Speaking to reporters ahead of Trump’s speech, Secretary of State Rex Tillerson said the president will use the Congressional Iran Nuclear Agreement Review Act to decertify the agreement, which was negotiated over 18 months by the Obama administration.

Congress could then decide to restore sanctions, do nothing or make changes to the law. Trump is pressing Congress to work to fix the deal's "flaws."

IRAN NUCLEAR DEAL: WHAT IS IT?

In making his decision, Trump said, “Iran is not living up to the spirit of the deal.” Among other alleged violations, Trump said Iran failed to meet expectations in its operation of advanced centrifuges and intimidated international inspectors into not using their full authority.

The president also slammed sunset provisions in the deal itself, complaining that the U.S. got a “weak inspection” in exchange for a “short-term” delay in Iran’s nuclear progress.

Trump, meanwhile, announced plans to take action against the Islamic Revolutionary Guard Corps, authorizing the Treasury Department to impose targeted sanctions against “its officials, agents, and affiliates.”

“Execution of our strategy begins with a long overdue step of imposing tough sanctions on Iran's Islamic Revolutionary Guard Corps,” Trump said. “The revolutionary guard is the Iranian supreme leader’s corrupt personal terror force and militia.”

In his broadside against the Iranian regime, the president said it “remains the world's leading state sponsor of terrorism,” accusing it of providing assistance to Al Qaeda, the Taliban, Hezbollah and other terrorist networks.

The president accused Iran of developing missiles that threaten American troops and allies and imprisoning Americans “on false charges.”

“Given the regime's murderous past and present, we should not take lightly its sinister vision for the future,” Trump said. “The regimes two favorite chants are ‘Death to America’ and ‘Death to Israel.’”

The president did not designate the IRGC a terrorist group, something that had been rumored ahead of the announcement. In the run-up to the decision, Iranian officials threatened consequences if that occurred.

“If the news is correct about the stupidity of the American government in considering the Revolutionary Guards a terrorist group, then the Revolutionary Guards will consider the American army to be like Islamic State all around the world,” IRGC commander Mohammad Ali Jafari said Sunday, according to Reuters.

The National Resistance Council of Iran, an offshoot organization of the People's Mojahedin Organization of Iran (MEK), praised Trump's move in support of the de-certification.

Mrs. Maryam Rajavi, President-elect of the National Council of Resistance of Iran (NCRI), welcomed the new U.S. policy to "condemn the IRGC's gross violations of human rights" in Iran.

"The regime's deadly meddling in the region and concessions made to it in the course of the JCPOA (Joint Comprehensive Plan of Action) have been disastrous, and for which the people of Iran and the region have paid heavily," Rajavi said in a statement provided to Fox News.

"The IRGC is a prime means of suppression, execution, and torture in Iran, spreading terrorism throughout the world, war mongering and massacre in the region, the drive for acquiring nuclear weapons, and the increase in the proliferation of ballistic missiles," she said. "If the IRGC had been recognized as a terrorist entity earlier and dealt with accordingly, the current situation in the region in general, and Iraq, Syria, Lebanon, Yemen, and Afghanistan in particular, would have been totally different."

Trump had been facing a Sunday deadline to notify Congress whether Iran is complying with the accord.

Republicans are calling for new legislation that addresses the “flaws” of the agreement.

“Lawmakers need to do now what we couldn’t do two years ago: unite around an Iran strategy that truly stops Iran’s nuclear weapons program and empowers the United States and our allies to combat the full spectrum of Iran’s imperial aggression,” Sen. Tom Cotton, R-Ark., said in a statement.

Democrats accused the president of making matters worse. Former Obama administration official Ben Rhodes, who helped sell the Iran deal, said the president is “provoking” a crisis with his speech.

“Hard to overstate how irresponsible it is for Trump to risk blowing up Iran Deal by demanding rest of world justify his campaign rhetoric,” Rhodes tweeted.

Fox News’ Serafin Gomez, Mike Emanuel and Perry Chiaramonte and The Associated Press contributed to this report.