The European Union and the United States on Saturday lifted the economic and oil sanctions imposed over three decades ago on Iran after the United Nations international atomic watchdog confirmed Tehran had followed through on all the terms of nuclear deal set by world powers in July last year.

"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 (IAEA) said in a statement.

The announcement was made after the IAEA conducted inspections at the nuclear sites in Iran to confirm if it aided by the Joint Comprehensive Plan of Action (JCPOA) planned in July.

"Today, I released a report confirming that Iran has completed the necessary preparatory steps to start the implementation of the Joint Comprehensive Plan of Action. It was issued after agency inspectors on the ground verified that Iran has carried out all measures required under the JCPOA to enable Implementation Day to occur," IAEA Director General Yukiya Amano said in a statement.

The agreement allows the IAEA to verify and monitor "Iran's nuclear-related commitments".

"In line with its commitments, Iran will start to provisionally implement the additional protocol to its safeguards agreement with the IAEA. Together with other nuclear-related measures under the JCPOA, this increases the Agency's ability to monitor nuclear activities in Iran and to verify that they are peaceful," Amano said.

As part of the deal, Iran has agreed to limit its uranium stockpile. It has also removed the core of the country's Arak nuclear reactor, which restricts it from producing nuclear bomb-grade plutonium.

Iranian President Hassan Rouhani on Saturday took to Twitter to congratulate his country on the victory. "Thank God for this blessing and bow to the greatness of the patient nation of Iran. Congrats on this glorious victory, (sic)" Rouhani tweeted in English.

Besides the lifting of the sanctions, the US and Iran swapped prisoners. US President Barack Obama pardoned three Iranian-Americans who were charged with violating sanctions against Iran, Reuters reported.

Iran, on its part, agreed to release five Americans, including Washington Post reporter Jason Rezaian and Iranian-American Christian pastor Saeed Abedini, who were sentenced to eight years in prison in 2013 on charges of undermining Iran's national security, according to the report.