Iranian Foreign Minister Mohammad Javad Zarif (L), International Atomic Energy Agency (IAEA) Director General Yukiya Amano and the High Representative of the European Union for Foreign Affairs and Security Policy Federica Mogherini arrive at the United Nations building in Vienna, Austria, January 16, 2016. [Photo/Agencies]

VIENNA/DUBAI - Iran emerged from years of economic isolation on Saturday when the UN nuclear watchdog ruled the Islamic Republic had curbed its nuclear programme under a deal with world powers, clearing the way for the lifting of crippling sanctions against Tehran.

In another sign of the easing of tensions between the West and Iran, Tehran and Washington announced an unexpected prisoner swap.

Iran will free five Americans including jailed Washington Post reporter Jason Rezaian and a Christian minister.

And in an unusual move, President Barack Obama pardoned three Iranian-Americans charged for violating sanctions against Iran, a lawyer for one of the men said, while prosecutors moved to drop charges against four Iranians outside the United States.

Sanctions on Iran by the United States, United Nations and European Union will be lifted within hours or days.

Mostly imposed in the last five years, the sanctions have cut off the country of 80 million people from the global financial system, reduced oil producer Iran's exports and imposed severe economic hardship on ordinary Iranians.

"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.