U.S. Denies Role in Iranian Nuclear Scientist's assassination

U.S. Denies Role in Iranian Nuclear Scientist's Assassination

 

Nuclear Scientist Killed in Iran

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Wednesday's attack comes during the highest tensions between the U.S. and Iran in decades, perhaps since Iran's revolution in 1979. This month, the U.S. imposed sanctions that bar companies from doing business with Iran's Central Bank and the European Union is discussing sanctions oil exports.

Iran has threatened to close off the Strait of Hormuz if its exports are blocked. The strait sees about one-fifth of the world's oil pass through it.

The head of Iran's military said last week that American naval ships would need their permission to pass through the strait -- an assertion the Pentagon rejected.

ABC News' Lee Ferran and Kirit Radia contributed to this report.