Iran informed on Tuesday the United Nations nuclear watchdog of its intention to increase its nuclear enrichment capacity.
The boost will remain within the limits of the 2015 nuclear deal.
Tuesday’s move appeared to be mainly aimed at signaling that Iran could resume its drive toward industrial-scale enrichment if the nuclear accord comes unraveled.
Behrouz Kamalvandi, the spokesman for Iran's nuclear agency, was quoted by state TV as saying a letter was submitted to the International Atomic Energy Agency detailing the move.
Kamalvandi said Iran is "providing infrastructure and arrangements for high-speed and capacity in production of UF4 and UF6 gases as well as rotor of centrifuges."
Spinning centrifuges convert the gases into enriched uranium that can be used for reactor fuel and medical isotopes. If enriched to higher levels, the material can be used for weapons.
"It is important to note that Iran will remain far from having the fissile material necessary for a nuclear weapon even if they increase their enrichment efforts as described," The Washington-based Arms Control Association said in a statement.
The head of Iran's nuclear agency, Ali Akbar Salehi, said Iran is prepared to resume work on advanced centrifuges that would dramatically increase its capacity for enrichment. But he said that so far, the work is limited to building a new facility for assembling the centrifuges.
Israeli Prime Minister Benjamin Netanyahu reacted swiftly to Salehi's announcement, declaring that the Tehran’s aim was "unlimited enrichment of uranium to create an arsenal of nuclear bombs" to destroy his country.
Supreme Leader Ali Khamenei had ordered the increase in capacity in a speech Monday, in which he vowed that Iran would preserve its nuclear program despite the US withdrawal from the landmark 2015 accord.
Under the 2015 agreement, Iran can only enrich uranium to 3.67 percent.
If it chooses to abandon the deal, it has stated it could "within days" return to enrichment of 20 percent -- still within the limits of civilian use but allowing for a much quicker jump to military-grade levels of around 90 percent.
