The World Today - Thursday, 22 March , 2007 12:18:00
Reporter: Michael Rowland
ELEANOR HALL: In the United States the Bush Administration is putting pressure on major oil companies to stop dealing with Iran.
It is part of the U.S campaign to persuade the Tehran regime to halt its nuclear program.
And it coincides with discussions in the United Nations Security Council about a package of new sanctions against Iran.
But Iran's supreme religious leader has merely answered these moves with more threats of his own.
As North America correspondent Michael Rowland reports.