At a news conference following President Trump's announcement, his Treasury Secretary Steve Mnuchin appeared to suggest that the sanctions would extend to the Iranian Foreign Minister later this week.
On June 20, an Iranian missile destroyed a U.S. Global Hawk surveillance drone in worldwide airspace, according to the Pentagon.
The attacks came shortly after the Islamic Revolution Guards Coprs (IRGC) shot down a US Navy RQ-4A global Hawk drone that had entered Iranian airspace in the Persian Gulf region to gather intelligence, using Khordad 3 indigenous surface-to-air missile system.
Both measures are widely seen as retaliation for the shooting down of an unmanned U.S. military drone by Iran's Islamic Revolutionary Guard Corps (IRGC) last Thursday as well as a recent spate of attacks on oil tankers in the Gulf of Oman, which the United States has blamed on Iran.
The latest sanctions are aimed at denying Iran's leadership access to financial resources and blocking them from using the USA financial system or assets.
On Thursday American outlets claimed that the United States had targeted computer systems that control Iranian rocket and missile launchers.
Trump also re-ordered economic sanctions on Iran. "If they want something beyond the JCPOA, they should offer something beyond the JCPOA; with worldwide guarantees", Hesameddin Ashena said, using the official name of the pact, the Joint Comprehensive Plan of Action, Reuters reported. But, I felt that we want to give this a chance, give it a good chance, because I think Iran potentially has a phenomenal future'.
Meanwhile, Secretary of State Mike Pompeo is in the Middle East today meeting with leaders from Saudi Arabia and the UAE.
Later, Trump said the sanctions would have been imposed regardless of the incident over the drone.
Washington has blamed Tehran for attacks on tankers in the Gulf in recent weeks, which Iran denies.
A multinational accord reached by Tehran and world powers in 2015 sought to curb Iran's nuclear ambitions in exchange for sanctions relief.
Mr Bolton said "Iran's silence has been deafening", on the proposed talks.
The moves came after Iran shot down a USA drone last week and Trump called off a retaliatory air strike minutes before impact, which would have been the first time the United States had bombed Iran in decades of hostility between them. "As President Trump said on Friday, our military is rebuilt, new and ready to go".
The US denies the drone, valued at more than $100 million, violated Iranian airspace.
As part of its campaign, the US has re-imposed sanctions on exports of Iranian crude oil, which has pushed Iran's economy into a nosedive.
It comes amid escalating tensions between the us and Iran in the Persian Gulf.
On Saturday, a spokesman for Iran's armed forces warned that a military strike would "set the region ablaze and burn up the United States, its interests, and its allies".
Speaking in Jerusalem, US National Security Adviser John Bolton said all Iran has to do is "walk through that open door" to enter negotiations with the US.
It was an apparent reference to a tweet in which Trump said other countries should protect their own oil shipping in the Middle East rather than have the United States protect them.
The deal was signed by his predecessor Barack Obama along with the UK, France, China, Russia and Germany, which still support the agreement.