(JNS) Iran’s efforts to produce enriched uranium metal have progressed, according to an International Atomic Energy Agency (IAEA) report released earlier this week.

According to the report, which was issued to member states, Iran has produced 200g of uranium metal—enriched up to 20%, Reuters reported.

In response, U.S. State Department spokesperson Ned Price called on Tehran to “cease its nuclear escalations and return to negotiations.”

“Iran has no credible need to produce uranium metal, which has direct relevance to nuclear weapons development,” said Price.

The production of uranium metal is a key step in the path to the development of nuclear weapons.

For its part, Iran insists that its work on uranium metal is part of an effort to develop a new type of reactor fuel, according to Reuters.

A confidential IAEA report first revealed Iran was working on uranium metal back in February. That was confirmed by another report, released in July.