Iran emerged from years of economic isolation on Saturday when world powers lifted crippling sanctions against the Islamic Republic in return for Tehran complying with a deal to curb its nuclear ambitions.
In a dramatic move scheduled to coincide with the scrapping of the sanctions, Tehran also announced the release of five Americans including Washington Post reporter Jason Rezaian as part of a prisoner swap with the United States.
Together, the lifting of sanctions and the prisoner deal considerably reduce the hostility between Tehran and Washington that has shaped the Middle East since Iran's Islamic Revolution of 1979.
Tens of billions of dollars worth of Iranian assets will now be unfrozen and global companies that have been barred from doing business there will be able to exploit a market hungry for everything from automobiles to airplane parts.
The U.N. nuclear watchdog ruled on Saturday that Iran had abided by an agreement last year with six world powers to curtail its nuclear program, triggering the end of sanctions.
"Iran has carried out all measures required under the (July deal) to enable Implementation Day (of the deal) to occur," the Vienna-based International Atomic Energy Agency said in a statement.
Within minutes, the United States formally lifted banking, steel, shipping and other sanctions on Iran, a major oil producer which has been virtually shut out of international markets for the past five years.
The European Union also began the process of lifting sanctions and Iran's transport minister said Tehran plans to buy 114 civil aircraft from European aircraft maker Airbus.
The end of sanctions means more money and prestige for Shi'ite Muslim Iran as it becomes deeply embroiled in the sectarian conflicts of the Middle East, notably in the Syrian civil war where its allies are facing Sunni Muslim rebels.