Reuters
In another sign of detente between the West and Iran, Tehran and Washington announced an unexpected exchange of prisoners.
Iran freed five US citizens, including the Washington Post correspondent Jason Rezaian as a Christian pastor.
In an unusual decision, the US president, Barack Obama pardoned three Iranian citizens for violating US sanctions against Iran, and prosecutors dropped charges against four Iranians who are outside the North American country.
Sanctions against Iran United States, the United Nations and the European Union will rise within hours or days.
The measures most applied in the past five years, have departed the country of 80 million people the world financial system, they abruptly cut their exports and imposed severe economic hardship to Iranians.
"Iran has taken all the required measures (by the agreement of July) to occur the 'Implementation Day'," said the International Atomic Energy Agency (IAEA) said in a statement.
With the lifting of sanctions, which have damaged the banking, energy and shipping, the oil producer will the global economic scene.
A strengthening Iran's economy can change the geopolitical balance in the Middle East, where Iran is the largest Shiite power with allies involved in conflicts in Iraq, Syria and Yemen, facing the main Sunni supporters power, Saudi Arabia .
More oil
Iran's return to a market with excess oil and is one of the factors that has contributed to a collapse in prices, which this week lost the mark of $ 30 a barrel for the first time in 12 years.
Tehran said it may increase exports by 500,000 barrels per day within weeks.
The agreement to lift sanctions is viewed with skepticism by allies of US Middle East, including Israel and Saudi Arabia.
However, it is supported by Washington's European allies who had previously supported Obama's decision to toughen the measures as part of a joint strategy to force Tehran to negotiate.
The Obama administration has said that the agreement was reached in July is the best chance to ensure that Iran does not develop a nuclear weapon.
Iran has denied that its nuclear program has the objective of developing an atomic bomb.