He gave no indication of how long the review would take or what the likely outcome would be.
"The evidence is clear: Iran's provocative actions threaten the United States, the region and the world", he said. Critics have said it's unfathomable that the US would grant sanctions relief to Tehran even as it continues testing ballistic missiles, violating human rights and supporting extremist groups elsewhere in the Middle East.
US Secretary of State Rex Tillerson claims that Iran nuclear deal does not achieve its goal of keeping Iran from obtaining a nuclear weapon, AP reports quoting sputniknews.
Tillerson told reporters the review, which he announced on Tuesday (18 April), would not only look at Tehran's compliance with a 2015 nuclear deal but also its behaviour in the region which he said undermined U.S. interests in Syria, Iraq, Yemen and Lebanon.
"Iran spends its treasure and time disrupting peace", he said.
"The U.S. Department of State certified to U.S. House Speaker Paul Ryan today that Iran is compliant through April 18 with its commitments under the Joint Comprehensive Plan of Action", Tillerson said in a statement.
Proponents of the deal say that abandoning it would make other challenges in the Middle East even harder, emboldening Iranian hardliners and triggering Iran to restart its nuclear program, which could start a nuclear race in the region as other countries rushed to get their own bomb.
The switch from the certification to criticism left Republicans on Capitol Hill, who had widely excoriated the agreement and voted against its implementation, with mixed responses.
The certification of Iran's compliance, which must be sent to Congress every 90 days, is the first issued by the Trump administration. Trump has criticized the Obama administration for a 2011 military intervention that he says created a power vacuum that led Libya to slip into chaos.
Secretary of State Rex Tillerson laid out a new approach to Iranian belligerence in a State Department press conference Wednesday.
Obama argued the deal was narrowly tailored to prevent what he said was the imminent emergence of a nuclear-armed Iran.
Opponents of the agreement have called for renegotiating the accord with the goal of making permanent its 15-year moratorium on uranium enrichment close to the level needed to make a bomb.
Iran has yet to comment on the Trump administration's latest round of criticism, but Iranian Supreme Leader Ayatollah Khamenei has warned that Tehran would retaliate if the United States breached the nuclear agreement.
However, the USA admits that Tehran is complying with the 2015 agreement.
The agreement was effectively dead before Trump took office after Congress refused to ratify it.
"It is their habit to unsettle people and nations", Tillerson said.
And, with a funding deadline looming to keep the government running, Trump said it was possible Congress would manage to accomplish it all next week or "shortly thereafter".
The president's comments came in a almost 20-minute news conference Thursday afternoon with Italian Prime Minister Paolo Gentiloni, with Trump weighing in on several global trouble spots, including Iran, North Korea and Libya.
"Iran has not lived up to the spirit of the agreement, and they have to do that, they have to do that", the president said.