(SOUNDBITE) (English) U.S. PRESIDENT DONALD TRUMP:
"What I would like to see with Iran: I would like to see them call me."
A day after U.S. President Donald Trump extended that invitation, Iran's Revolutionary Guards responded saying 'no.'
A Guards' official on Friday said Tehran will not negotiate with the U.S. and also claimed that the U.S. would not dare take military action against Iran.
The spat comes amid news that B-52 bombers ordered by the White House have reached a U.S. base in Qatar to counter what Washington describes as threats from Iran.
The U.S. said earlier this week that a number of B-52 bombers would be part of a buildup of forces in the Middle East after U.S. intelligence signaled that Iran was possibly making plans to attack American troops.
(SOUNDBITE) U.S. SECRETARY OF STATE MIKE POMPEO SAYING ON MONDAY:
"We have continued to see activity that leads us to believe that there may be escalation that is taking place and so we're taking all the appropriate actions."
Iran has dismissed the move - accusing the U.S. of trying to intimidate through 'psycological warfare.'
The U.S. on Wednesday slapped sanctions on Iranian industrial metals following Tehran's announcement that it would scrap some of its commitments to the 2015 nuclear pact.
That coming just one year after President Trump withdrew from the agreement.