Iran emerged from years of economic isolation on Saturday when the U.N. 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.

Iran’s FM JavaIn another sign of the easing of tensions between the West and Iran, Tehran and Washington announced an unexpected prisoner swap.

It’s a deal: FM Zarif with US Secretary of State John Kerry in Vienna today

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.

Iran has taken sufficient steps to prevent it from building a nuclear weapon, the United Nations’ nuclear watchdog certified Saturday, opening the door for the United States and countries around the world to lift sanctions that have crippled Iran’s economy.

After decades of tensions, years of negotiations and months of work to implement the international nuclear deal reached six months ago, Iran has fulfilled its promises, the International Atomic Energy Agency (IAEA) said.

The State Department confirmed moments later that the nuclear deal is now implemented.

In Vienna, Secretary of State John Kerry touted the step as a vindication of diplomacy in the face of doubters.

“I think we have also proven once again why diplomacy must be our first choice and war a last resort,” Kerry said.

“Iran has undertaken significant steps that many, and I do mean many, people doubted would ever come to pass,” he added.

Iran’s level of enriched uranium is two percent of what it was before the agreement, Kerry said while pointing to a range of steps Iran has taken.

“Iran has taken every step that it committed to take dating back two full years,” Kerry said.

He added: “Today marks the first day of a safer world.”

The milestone to fully implement the nuclear accord comes despite heated opposition on Capitol Hill and around the country.

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.

The strengthening of Iran’s economy 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 those who back its main Sunni Muslim regional rival, Saudi Arabia.

Iran’s 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.

The sanctions deal is viewed with deep suspicion by U.S. allies in the Middle East including Israel and Saudi Arabia. It is, however, supported by Washington’s European allies, who joined Obama earlier in his presidency in tightening sanctions as part of a joint strategy to force Tehran to negotiate.

Reported by AP and Reuters