The European Union says a “first assessment” indicated that Iran’s declared intention to increase uranium enrichment capacity did not violate Tehran’s commitments under a landmark nuclear agreement it signed with major world powers in 2015.

A spokeswoman for the European Union foreign policy chief Federica Mogherini said on Tuesday that Iran’s decision did not constitute a breach of the nuclear agreement, officially known as the Joint Comprehensive Plan of Action (JCPOA).

“Following a first assessment, the announced steps per se are not a violation of the JCPOA,” Maja Kocijancic told AFP.

“However, at this particularly critical juncture, they will not contribute to build confidence in the nature of the Iranian nuclear program,” she claimed.

The European Union is working to save the agreement after US President Donald Trump’s move to withdraw from it. Since the US president pulled Washington out of the historic nuclear deal, European countries have been scrambling to ensure that Iran gets enough economic benefits to persuade it to stay in the deal. The remaining parties have vowed to stay in the accord.

The Atomic Energy Organization of Iran (AEOI) said on Tuesday that the country has begun work to prepare the infrastructure for building advanced centrifuges at its Natanz enrichment facility, while respecting its commitments under the JCPOA.