In this file photo taken on January 20, 2014, an unidentified International Atomic Energy Agency (IAEA) inspector disconnects the connections between the twin cascades for 20 percent uranium production at nuclear power plant of Natanz, some 300 kilometres south of Tehran. (AFP photo)

TEHRAN, June 5 (Xinhua) -- Iran's atomic chief said here Tuesday that the Islamic republic is preparing the infrastructure for building advanced centrifuges, Press TV reported.

The work has begun at Iran's Natanz enrichment facility, observing the country's commitments to 2015 nuclear deal, Ali Akbar Salehi, head of Atomic Energy Organization of Iran (AEOI) said.

"Yesterday, we took the first step and submitted a letter to the International Atomic Energy Agency (IAEA) on the start of certain activities, but we started to take the necessary practical measures today," Salehi was quoted as saying.

"If conditions are ripe, I may explain tomorrow night at Natanz one of the projects we have in mind, which is a center for the production of new centrifuges," he said.

Iran's supreme leader Ayatollah Ali Khamenei on Monday ordered the AEOI to prepare for the enrichment of uranium up to a level of 190,000 SWU (separative work units).

Iran is holding negotiations with European countries on preserving the 2015 Iranian nuclear deal, officially known as the Joint Comprehensive Plan of Action (JCPOA), after the U.S. pullout in May.