Press TV - The US has imposed sanctions on seven companies along with three individuals it claims helped procure materials for Iran’s nuclear program.

“Treasury is taking action to shut down an Iranian nuclear procurement network that leverages Chinese- and Belgium-based front companies to acquire critical nuclear,” Treasury Secretary Steven Mnuchin said in a statement on Thursday.

“Iran cannot claim benign intent on the world stage while it purchases and stockpiled products for centrifuges,” Mnuchin added.

This marked the first time Washington imposed sanctions on Iran since Tehran announced it would surpass the uranium stockpile limit set under the Iran nuclear deal the United States quit last year.

In May, Iran informed the five remaining signatories to the 2015 nuclear deal - the UK, Germany, Russia, China and France - of its decision to suspend the implementation of some of its commitments under the agreement, exactly one year after the United States unilaterally abandoned it.

Iran warned that in 60 days it would resume refining uranium to a higher fissile degree if Europe failed to shield its trade from US sanctions.

On June 17, the spokesman for the Atomic Energy Organization of Iran said, "Today the countdown to pass the 300 kilograms reserve of enriched uranium has started and in 10 days time we will pass this limit."

"This is based on the Articles 26 and 36 of the (nuclear deal), and will be reversed once other parties live up to their commitments," Behrouz Kamalvandi told reporters at the Arak Heavy Water Reactor Facility.

Iran may also increase uranium enrichment to up to 20 percent for use in local reactors, he said. The  nuclear accord caps the level of purity to which Iran can enrich uranium at 3.67 percent.

"One scenario is that we will define 3.67 for the Bushehr power station, which needs 5 percent [enriched uranium] or if we define for the needs of the Tehran Research Reactor, it will be 20 percent. Various scenarios have been envisaged,” he noted.