Trump notified Congress that he is "decertifying" the deal, known as the Joint Comprehensive Plan of Action, arguing that while Iran may be complying with the letter of the agreement, the accord itself is not sufficient to be in U.S. interests. Trump's announcement "once again underlines the inadmissibility of using aggressive and threatening rhetoric in international relations", Russia's foreign ministry said in a statement.
McCain pointed to Iran's support for the government of Syrian President Bashar Assad, saying Tehran "has contributed to hundreds of thousands of deaths and the displacement of millions, destabilizing nations across the Middle East". Trump has the right, he said, to try to fix a deal that many see as flawed.
Saudi Arabia also welcomed what it called Trump's "decisive strategy" towards Iran and said lifting sanctions had allowed Tehran to develop its ballistic missile program, step up its support for militant groups including Hezbollah and the Houthis in Yemen, and attack global shipping lanes.
"We will not continue down a path whose predictable conclusion is more violence more terror and the very real threat of Iran's nuclear breakout", Trump said.
Two influential Republican senators have drawn up a plan for sanctions that European diplomats fear would amount to a repudiation of the 2015 international accord, but it is unclear whether they could muster a majority.
In a Senate hearing earlier this month, Secretary of Defense James Mattis said it was in the national interest to stay in the agreement. Deal opponents say that because Iran sells the surplus on the open market, Iran is therefore being rewarded for violating the deal. It was not clear how he would respond to the legislation.
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 directed U.S. intelligence agencies to probe whether Iran might be working with North Korea on its weapons programs.
"I think that we have provided a route to overcome deficiencies and to keep the administration in the deal, and actually make it the kind of deal it should have been in the first place", Corker said.
The United States has formally added Iran's Islamic Revolutionary Guards Corps (IRGC) to its antiterrorism sanctions list.
Perhaps more important, Iranian contacts have told me that if Europe reaffirms its compliance with the deal (as the three leaders just did), and Congress (as expected) doesn't legislate new sanctions, then Iran is likely to remain in compliance, too.
But "in time, he will find kindred spirits or people who will be more aligned with what he wants to do", says Wright. He noted that U.S. participation in the deal "can be canceled by me as president at any time".
His speech, Rouhani charged, "showed the JCPOA is much stronger than what this gentleman thought of the deal in the presidential campaign".
The president, who took office in January, had reluctantly certified the agreement twice before but has repeatedly blasted it as "the worst deal ever".
"Congress has already begun to work to address these problems", Mr. Trump said, adding that key members of Congress are already working to amend INARA. Secretary Tillerson has denied the threat, but pointedly did not deny the slur on Trump's intelligence (although his State Department spokeswoman did deny it).
There are some signs that Iran is feeling the pressure from the president's decision.
HOUSE MINORITY LEADER NANCY PELOSI: Supported the original deal, still supports it.