 Another warning from the US to Iran regarding nuclear weapons, US Secretary of State Anthony Blinken said it was up to Iran to engage to deal with the challenge of its nuclear program. We continue to believe that with regard to the nuclear program, the most effective, sustainable way to deal with the challenge is through diplomacy. But at this moment, those efforts are on the back burner, because Iran is simply not engaged in a meaningful way. But the door is always open to diplomacy going forward. A lot depends on what Iran says and does and whether or not it engages. Blinken told a news conference during a visit to Athens. The Secretary of State's comments come days after Bloomberg News reported that Iran has enriched uranium to levels just below that needed for a nuclear weapon. According to two senior diplomats, inspectors of International Atomic Energy Agency, IAEA, need to determine whether Iran intentionally produced the material, uranium enriched to 84% purity or whether it was the result of an unintended accumulation within the centrifuges. Uranium of 84% purity is the highest level found by inspectors in Iran to date and just 6% below what's required for a weapon. Iran had previously told the IAEA that its centrifuges were configured to enrich uranium to a level of purity of just 60%.