The New York Times reported:

Iran’s surprise move this week to begin enriching its uranium to a level closer to weapons-grade violated an agreement with atomic inspectors in Vienna, diplomats said, very likely providing the United States with another piece of evidence that Iran is not living up to its international commitments on its nuclear program.

The breach involved Iran’s starting the enrichment process in the absence of atomic inspectors — something that the International Atomic Energy Agency had specifically asked Iran not to do. Narrowly, the violation was viewed as technical in nature. But it caused resentment at the atomic agency’s headquarters in Vienna because Iran had acted so quickly and with such apparent contempt of the agreement.

“There’s a feeling of pique and annoyance,” said a European diplomat who works with the agency and spoke on condition of anonymity, because he was not authorized to speak with reporters.