UN inspectors have discovered fresh evidence of undeclared nuclear activities in Iran reports the Wall Street Journal. The discovery was made by several diplomats who were briefed on the findings. The activity raises questions about the ambitions of Tehran’s atomic aims.

Samples collected from two different sites during the inspections toward the end of last year by the United Nation’s International Atomic Energy Agency (IAEA) consisted of traces of radioactive material, the diplomats reported. The matter can be an indication that Iran has begun building nuclear weapons, based on its location. The diplomats admitted that they did not know the precise nature of the material that was found.

After the report came out, a cryptic message in what many are saying is a veiled threat against America was tweeted by Iran’s Supreme Leader Ayatollah Ali Khamenei saying “The post-U.S. era has started.”

The post-U.S. era has started.

— Khamenei.ir (@khamenei_ir) February 7, 2021

The mysterious message could be an acknowledgement of what Iran perceives as a weakening America under President Biden’s leadership. It can also be a veiled threat that’s connected to their nuclear ambitions.