(CNN) Iran is using advanced models of centrifuges to enrich uranium, President Hasan Rouhani confirmed today.

The move marks another breach of the 2015 nuclear agreement which lifted economic sanctions against Iran in exchange for strict limits on the country's nuclear program.

In 2018, President Donald Trump withdrew from the agreement, formally known as the Joint Comprehensive Plan of Action (JCPOA) -- a move which Iran says nullified its own obligations. Trump has since reinstated sanctions on Iran.

Iran has already taken steps that are in breach of the landmark deal. It started increasing uranium enrichment beyond the purity threshold it originally agreed to, and has increased stockpiles of low-enriched uranium above the deal's limits.

"The third step in the decrease of JCPOA commitments by us was that the limitations that we had vis a vis research and development; within the framework of the JCPOA we have left those limitations," Rouhani told journalists at a press conference in New York City.

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