By Bozorgmehr Sharafedin and Lesley Wroughton
DUBAI/WASHINGTON (Reuters) - Three Iranian-Americans left Tehran on Sunday under a prisoner swap following the lifting of sanctions on Iran that is likely to thaw ties further with the United States as Tehran emerges from years of international isolation.
A U.S. official said the Swiss plane had left carrying Jason Rezaian, the Washington Post's Tehran bureau chief, Saeed Abedini, a pastor from Idaho and Amir Hekmati, a former Marine from Flint, Michigan, as well as some family members.
One more Iranian-American released under the same swap, Nosratollah Khosravi-Roodsari, was not aboard the aircraft.
A fifth prisoner, the American student Matthew Trevithick, was released separately from the other four on Saturday, a U.S. official said.
"We can confirm that our detained U.S. citizens have been released and that those who wished to depart Iran have left," a senior U.S. administration official said. Iranian Foreign Minister Mohammad Javad Zarif told CNN as the plane was about to depart.
Several Iranian-Americans held in U.S. prisons after being charged or convicted for sanctions violations have also been released, their lawyers told Reuters on Sunday.
The prisoner deal was the culmination of months of diplomatic contacts, secret talks and legal maneuvering which came close to falling apart because of a threat by Washington in December to impose fresh sanctions on Iran for recent ballistic missile tests.
Speaking to parliament earlier on Sunday, Iranian President Hassan Rouhani hailed the nuclear deal with world powers and the resulting lifting on Saturday of U.S., European and United Nations sanctions as a "golden page" in Iran's history.
Rouhani, a pragmatist elected in 2013 on promises to end Iran's years of sanctions and isolation, said he looked forward to an economic future less dependent on oil exports.
These are nevertheless likely to jump now that the United States, European Union and U.N. have scrapped the crippling sanctions in return for Tehran complying with the deal to curb its nuclear ambitions.
But Rouhani noted bitter opposition to the lifting of economic curbs from arch foe Israel, some members of the U.S. Congress and what he called "warmongers" in the region - an apparent reference to some of Iran's Gulf Arab adversaries.
Presenting the draft budget for the next Iranian fiscal year, which begins in March, Rouhani told parliament the deal was a "turning point" for the economy of Iran, a major oil producer which has been virtually shut out of international markets for the past five years.
"The nuclear negotiations which succeeded by the guidance of the Supreme Leader and support of our nation, were truly a golden page in Iran's history," he said.
"The nuclear deal is an opportunity that we should use to develop the country, improve the welfare of the nation, and create stability and security in the region," Rouhani said.
Together, the lifting of sanctions and the prisoner deal help to ease the hostility between Tehran and Washington that has shaped the Middle East since Iran's 1979 Islamic Revolution.
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.
CROWNING ACHIEVEMENT FOR ROUHANI
America's thaw with Iran is viewed with deep suspicion by U.S. Republicans as well as allies of Washington in the Middle East, including Israel and Saudi Arabia. U.S.-Iranian suspicion still remains deeply entrenched.
Israel's opposition was evident in a statement from the office of Prime Minister Benjamin Netanyahu on Saturday night.
"Even after the signing of the nuclear agreement, Iran has not abandoned its aspirations to acquire nuclear weapons, and continues to act to destabilize the Middle East and spread terrorism throughout the world while violating its international commitments," the statement said.
Rouhani took a swipe at its critics. "Everybody is happy except the Zionists, the warmongers who are fuelling sectarian war among the Islamic nation, and the hardliners in the U.S. congress," he said.
The International Atomic Energy Agency ruled on Saturday that Iran had abided by last year's agreement with six world powers to curtail its nuclear program, triggering the end of sanctions.
IAEA chief Yukiya Amano will travel to Tehran on Sunday to meet Rouhani and the head of the Atomic Energy Organisation of Iran, the IAEA said on Saturday.
Minutes after the IAEA's ruling, the United States formally lifted banking, steel, shipping and other sanctions on Iran. The EU likewise ended all nuclear-related economic and financial sanctions against the country. Most U.N. sanctions also automatically ended.
MORE MONEY, PRESTIGE FOR IRAN
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.
It is also a crowning achievement for Rouhani, a pragmatic cleric elected in 2013 in a landslide on a promise to reduce Iran's international isolation.
Iran denies its nuclear program was aimed at obtaining an atomic bomb. Washington maintains separate, less comprehensive sanctions on Iran over its missile program.
Britain welcomed the deal's implementation, as did France which said it would keep a close eye out to ensure that the deal is strictly respected. Japan plans to lift most of its sanctions against Iran, including a halt to fresh investments in Iranian oil and gas projects, "within a few days", a Foreign Ministry official said.
The European Commission said it would undertake a first "technical assessment mission" in February to explore energy ties with Iran. The EU executive is particularly keen to develop Iranian energy supplies as an alternative to Russia, whose powerful role as supplier of around a third of the EU's oil and gas has divided the bloc.
In Washington, President Barack Obama pardoned three Iranian-Americans charged with 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 agreed to free five Americans including Rezaian and Abedini, an Iranian-American Christian pastor sentenced to eight years in prison in 2013 on charges of undermining Iran's national security.
(Additional reporting by Sam Wilkin in Dubai, Parisa Hafezi in Ankara, Kiyoshi Takenaka in Tokyo, Dan Williams in Jerusalem; Writing by Yara Bayoumy, Editing by William Maclean and David Stamp)