The United Nations' nuclear watchdog on Saturday confirmed that Iran has curtailed its nuclear program as agreed with world powers, paving the way for the almost immediate lifting of crippling sanctions on the Islamic Republic.
"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.
The announcement triggers the lifting of sanctions imposed by the United States, United Nations and European Union within hours or days.
Earlier on Saturday, Iran and the United States eased decades of tension with the announcement of a prisoner swap.
With the removal of the sanctions, oil-producer Iran will now be back on the world economic stage.
Photos of 10 detained U.S. sailors:
The sanctions, mostly imposed in the last five years, have cut off the country of 80 million people from the global financial system, drastically reduced Iran's exports and imposed severe economic hardship on ordinary Iranians.
Iran's emergence from economic isolation could shift the geopolitical balance of the Middle East where Iran is the leading Shi'ite Muslim power and its allies are fighting proxy wars in Iraq, Syria and Yemen against allies of its main Sunni Muslim regional rival, Saudi Arabia.
Leading up to the sanctions announcement, the United States and Iran took steps to thaw the cold relations between the two countries which have frequently locked horns since Iran's Islamic Revolution of 1979.
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.
Iran will also free five Americans including Washington Post reporter Jason Rezaian and a Christian minister.
Iran's expected return to an already glutted oil market is one of the factors contributing to a global rout in oil prices, which fell below $30 a barrel this week for the first time in 12 years.
Tehran says it could boost exports by 500,000 barrels per day within weeks.