The Iranian flag waves outside of the UN building that hosts the International Atomic Energy Agency, IAEA, office inside in Vienna, Austria, July 10, 2019.
The Iranian flag waves outside of the UN building that hosts the International Atomic Energy Agency office inside in Vienna, Austria, July 10, 2019.

The U.N. nuclear monitoring agency says Iran has begun using advanced centrifuges to enrich uranium, a violation of a landmark agreement with world powers.

An International Atomic Energy Agency report, obtained by the French news agency and Reuters, said technologically advanced centrifuges at Iran's Natanz facility "were accumulating or had been prepared to accumulate enriched uranium."

The report also says Iran intends to use more of the advanced centrifuges than previously disclosed.

The developments breach a landmark deal world powers reached in 2015 that places limitations on Iran's nuclear program in exchange for sanctions relief.

The accord only allows Iran to stockpile enriched uranium in its first-generation centrifuges.

A security car passes in front of the Natanz nuclear facility located 300 kilometers (185 miles) south of Tehran, Nov. 20, 2004.

The report documents the latest in a series of Iran's violations of the agreement since U.S. President Donald Trump withdrew from the deal in 2018 and reimposed sanctions, believing Iran once had a nuclear weapons program that it canceled.

The remaining countries that signed the deal — Britain, China, France, Germany and Russia — have tried to preserve the pact.

Iranian government spokesman Ali Rabiei said on state television Wednesday that Tehran is willing to reassure parties to the deal it would not pursue the development of nuclear arms and accept changes to the accord if the U.S. returns to the deal and lifts sanctions.