Washington's so-called "snapback" sanctions are due to be reinstated against Tehran at 12:01 a.m. EDT on Tuesday, a US Treasury official said, speaking on condition anonymity.
Pompeo, who was en route to Washington after attending a summit in Singapore, said the White House would detail the sanctions in an announcement scheduled for August 6, although he did not immediately disclose the time.
He said: "It's an important part of our efforts to push back against Iranian malign activity".
Iran Air said on Saturday it was set to take delivery of five new planes from Franco-Italian firm ATR just before the renewed U.S. sanctions go into effect.
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Chelsea boss Maurizio Sarri admitted on Friday he was unsure if Courtois, who is yet to feature in pre-season, would return to the club he joined in 2014.
Trump pulled the United States out of the deal in May, saying Iran was not living up to the spirit of the accord and vowed to reimpose sanctions.
Today's tranche of sanctions - the first of two sets, with others coming into effect on 4 November - would affect the purchase of U.S. dollars, trade in gold and certain other metals, as well as aviation and the vehicle industry.
The United States has told other countries they must halt imports of Iranian oil starting in early November or face USA financial measures.
Trump has said he would be willing to meet with Iranian President Hassan Rouhani anytime without preconditions. According to his taunting tweets, Zarif assiduously worked the room in Singapore, urging countries to continue doing business with Iran even after the resumption of USA sanctions.
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The drive has intensified since Trump withdrew on May 8 from the 2015 nuclear deal between Tehran and world powers. Trump's comments to Bolton match with the rhetoric he pumped out on Twitter .
"An informed diplomatic source said Sunday that Saudi Arabia had agreed to grant a visa to the head. of Iran's interests section", reported the state-owned IRNA Iranian news agency adding that "Observers saw this.as a positive diplomatic step in Tehran-Riyadh relations".
"This is just about Iranians' dissatisfaction with their own government, and the President is pretty clear, we want the Iranian people to have a strong voice in who their leadership will be".
Writing on Twitter later that day, he said the United States was "deeply concerned about reports of Iranian regime's violence against unarmed citizens" and urged respect for human rights.
State media report that protesters attacked and tried to burn down a seminary in the area on Friday night, and that at least one person was killed by demonstrators, according to officials.
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One showed a cellphone video of a drone hovering over a residential street two blocks away and then crashing into a building. Both Cuban leaders expressed their "full solidarity and unconditional support for President Maduro", it said.
Iranian authorities have barely mentioned days of protests in the major cities of Isfahan, Shiraz, Mashhad and Tehran, driven by concerns over water, the economy and wider anger at the political system.