President Trump unveiled a sweeping and aggressive new policy toward Iran on Friday, saying he will not re-certify the nuclear deal signed in 2015 and calling for a variety of new sanctions against the government in Tehran.

"As I have said many times, the Iran deal was one of the worst and most one-sided transactions the United States has ever entered into," Trump said during a speech at the White House.

Saying the Islamic government in Tehran is dedicated to "death, destruction, and chaos all around the globe," Trump announced that the United States is adding new sanctions directed against Iran's Revolutionary Guard, which he called a supporter of international terror. The president also said he has started an investigation into whether Iran is cooperating with North Korea's nuclear weapons program.

The move, which Trump had hinted at for months, stirred immediate opposition from some of the United States' major allies, as the governments of France, Germany and United Kingdom all said they still back the nuclear agreement.

Iran President Hassan Rouhani, meanwhile, denounced Trump's speech, saying in a nationally televised address that it "contained nothing but expletives and a pile of delusional allegations against the Iranian nation."

Rouhani, despite criticizing Trump's speech, said Iran will continue to adhere to the agreement.

Despite Trump's claims of a nine-month review of Iran strategy, the new plan doesn't change much, some foreign policy analysts said. The nuclear deal still stands, and there are no signs Congress and Iran are willing to change it.

"The entire process he just put us through did great damage," said Ilan Goldenberg, Middle East Security Director with the Center for a New American Security. "He shook pretty much everybody's confidence."

Goldenberg, who worked on Iran issues at the Pentagon during President Barack Obama's administration, said Trump and his team "basically managed to alienate everyone, without really accomplishing anything."

Trump did not ask Congress to re-impose economic sanctions on Iran right away, but he did call for new requirements on Iran in an effort to "strengthen enforcement" of the agreement he has long criticized.

If there is no deal with Congress and U.S. allies, Trump said, "the agreement will be terminated." He then told reporters after the speech he is still willing to rip up the deal, but "we'll see what happens."

European leaders want to keep the deal. In the joint French-German-British statement, they said they have asked their foreign ministers to "consider with the US how to take these issues forward."

Dumping issue on Congress

Trump called the new approach part of a new strategy to deal with what he called the Iranian "dictatorship," even though Iran has a government that is more democratic than some U.S. allies in the region, such as Saudi Arabia. He cited the 1979 takeover of the U.S. embassy in Tehran and other threats.

He also contradicted the recent comments of secretaries of Defense Jim Mattis and State Rex Tillerson that Iran has complied with the nuclear deal, when he claimed Iran has tried to evade the agreements requirements.

Some Trump critics described the Iran plan as part of pattern: He chips away at various programs, whether it's health care, immigration, or the Iran deal, then throws the issues to Congress to accept or change.

“I wish containing Iran’s nuclear ambitions was a task as easy as some politicians make it seem," said Rep. Tim Ryan, D-Ohio. "The Iran Nuclear Agreement is not perfect, but remains our best chance for lasting peace and nuclear nonproliferation in Iran."

Trump backers applauded the president for seeking to get tough with Iran and improve the nuclear agreement.

Sen. Tom Cotton, R-Ark., said he backs legislation to address "the major flaws in the original Iran deal: the sunset clauses, the weak inspections regime, and the failure to restrict Iran's development of advanced centrifuges."

Trump faced a Sunday deadline to certify the agreement. Every 90 days, the president must certify that Iran is in compliance of the deal.

Tillerson said the United States wants to fix problems in the agreement, but that Trump is "not particularly optimistic" about the chances.

The United States signed the agreement in 2015 along with Russia, China, Germany, France and Great Britain. It called for the elimination of economic sanctions Iran in exchange for Tehran giving up its nuclear weapons program.

Rouhani, who says Iran's nuclear program has always been designed for peaceful energy purposes, said in September that international trust in the United States will be damaged if it walks away from the deal.

That's because, Rouhani told NBC News, so many countries had analyzed the deal in great detail before it was signed.

And allies fear that killing the agreement could prompt Iran to resume its nuclear weapons program, perhaps triggering a nuclear arms race throughout the Middle East.

Options for Congress

De-certification does not kill the deal outright; that would be up to Congress.

Tillerson said lawmakers have three options:

• Do nothing and refuse to put new sanctions on Iran, which would preserve the current agreement.

• Re-impose economic sanctions, which would kill the deal.

• Push to negotiate new terms that Trump believes will "put more teeth" in the demands on Iran.

One possible provision would be adding "trigger points," new rules that would lead to an immediate re-imposition of sanctions if Iran violates them. One example, Tillerson said, would be development of prohibited ballistic missiles.

Some U.S. officials also want to eliminate "sunset provisions" in the existing agreement, which allow Iran to resume its nuclear program after a decade or more.

There is no sign U.S. allies or Iran have any interest in new talks, much less a new deal.

Multiple issues with Iran

The Trump administration is concerned with more than just the nuclear agreement, Tillerson said. Trump and his aides have criticized Iran's ballistic missile program, which is not covered by the nuclear deal, as well as its support for what they call terrorism and efforts to destabilize Iraq, Syria and Yemen.

They have also cited Iranian threats toward Israel, a notably vocal opponent of the nuclear agreement.

Tillerson and National Security Adviser H.R. McMaster said they have discussed their new Iran approach with members of Congress. While a new agreement may not be possible, they said some lawmakers have been receptive, and improving the agreement is worth a try in any case.

Said McMaster: "Nobody's for Iran getting nuclear weapons."