Tehran says it will inform the UN nuclear watchdog on Tuesday of its plan to increase capacity to produce uranium.

Iran will inform the United Nations nuclear watchdog in Vienna on Tuesday of its plan to begin the process of increasing the country’s uranium enrichment capacity within the limits of the nuclear agreement, the country’s atomic energy agency spokesman has said.

“In a letter that will be handed over to the International Atomic Energy Agency (IAEA) … Iran will announce that the process of increasing the capacity to produce … UF6 (uranium hexafluoride) … will start on Tuesday,” Behrouz Kamalvandi told ISNA news agency.

He said Iran had the capacity to accelerate production of centrifuges, which are used to enrich uranium. The UF6 is raw material for centrifuges.

“The leader meant that we should accelerate some process … linked to our nuclear work capacity to move forward faster in case needed,” Kamalvandi said, referring to Supreme Leader Ayatollah Ali Khamenei.

On Monday, Khamenei had ordered Iran’s nuclear agency to “make the necessary arrangements” on enrichment.

But he also emphasised that it will be within “the framework provided” by the Joint Comprehensive Plan of Action (JCPOA), also known as the nuclear deal signed in 2015.

In his speech, Khamenei said Iran “will not tolerate being under sanctions, while limited in the nuclear field”.

European signatories of the accord back the deal, but have concerns over Iran’s ballistic missile programme and its influence in the Middle East.

‘We will strike back’

Iran says the two issues are non-negotiable, and Khamenei reiterated that point on Monday saying that the “missiles are for our own security and our strength”.

“The enemy must know, if they strike us just once, we will strike back 10 times fold!”

Under the 2015 nuclear agreement with the United States, France, Germany, Britain, Russia and China, Iran strictly limited uranium enrichment capacity to satisfy the powers that it could not be used to develop atomic bombs.

In exchange, Iran received relief from sanctions, most of which were rescinded in January 2016.

The deal allows Iran to continue 3.67 percent uranium enrichment, far below the roughly 90 percent threshold of weapons-grade. Before the deal was reached, Tehran enriched uranium to up to 20 percent purity.

Since President Donald Trump‘s announcement of the US withdrawal from the deal on May 8, European leaders have pledged to try to keep Iran’s oil trade and investment flowing, but admitted that will not be easy to do.

Tehran has complained that it has not benefited financially from the deal even before Trump’s decision to withdraw.

Mostafa Khoshcheshm, political commentator from Iran, told Al Jazeera that Khamenei declared Iran has a number of demands to keep the JCPOA alive.

“Most of the demands fall within the undertakings that the western governments have taken up under the JCPOA,” Khoshcheshm said.

“The most important one is ensuring Iran’s crude sale to the European states…and objective guarantees beyond what has been stated in the JCPOA.”

Iranian authorities have also warned that if the European countries failed to keep the pact alive, Tehran had several options, including resuming its 20 percent uranium enrichment.

“The Iranian leader never bluffs. Whenever he speaks of an action it happens, and now the ball is in the European court,” Khoshcheshm added.