"Despite my strong inclination, I have not yet withdrawn the United States from the Iran nuclear deal", Trump said in a statement, warning that the options were to fix "the deal's disastrous flaws, or the United States will withdraw".
Trump said that his decision will give Tehran and America's European allies time to fix the deal's "terrible flaws".
One senior administration official said Trump would be open to remaining in a modified deal if it were made permanent.
This would involve negotiations between the United States and its European allies rather than talks with Iran, the official said. It is also wants to address Iran's ballistic missile programme.
"This could be one of Washington's big foreign policy mistakes, a big miscalculation", said Deputy Foreign Minister Sergei Ryabkov, adding that Russian Federation would work hard to keep the agreement alive.
"The United States will not stand by while the Iranian regime continues to engage in human rights abuses and injustices", a second administration official said, saying some Iranian citizens are in prison "solely for expressing their rights to assembly".
Bhala can discuss why the president's position is wrong as well as the requirements of the deal for the U.S., Iran and worldwide allies.
A decision to withhold a waiver would have effectively ended the deal that limits Iran's nuclear program.
Europeans say these issues should be kept separate from discussion of the deal, but in a nod to U.S. concerns, Mogherini stressed they were raised with Zarif on Thursday.
Britain, France and Germany had called on Trump on Thursday to uphold the pact.
US presidents, under existing American law, must waive the sanctions every few months to prevent them from causing Iran to declare the nuclear pact violated and simply walk away to resume pursuit of an atomic arsenal.
But he said he would work with European allies to remove so-called "sunset clauses" that allowed Iran to gradually resume advanced nuclear activities in the next decade.
Iran's Foreign Ministry said on Saturday that Iran will never renegotiate the 2015 nuclear deal, formally known as JCPOA, despite the USA pressures.
That balance is aimed at satisfying Trump's demand to raise pressure on Iran, while not embarking on a frontal assault on the most central trade-offs of the nuclear agreement.
The Trump administration also announced a round of sanctions aimed at Iranian figures who had helped suppress recent street demonstrations that turned violent.
Recent Tunisia arrests over wave of unrest
The trigger of the protests was a finance law imposing tax hikes after a year of rising prices on fuel and some consumer goods. One man died in the unrest on Monday night, but the authorities have insisted the police were not responsible for this.
Eliza Dushku Claims She Was Molested by a Stuntman at Age 12
Rasmussen responded to a comment critical of her parenting on Eliza's original post, writing, "I was afraid of Joel Kramer , too". This shit has been going on since Day One. "I am grateful to the women and men who have gone before me in recent months".