The International Atomic Energy Agency has been responsible for policing the Iran deal. It has sealed some equipment, preventing its use, and installed cameras and other electronic monitoring.

A picture shows the seal of the connections between the twin cascades for 20 percent uranium production bearing the initials of the International Atomic Energy Agency (IAEA) after they were disconnected at nuclear research centre of Natanz, some 300 kilometres south of Tehran on January, 20, 2014 as Iran halted production of 20 percent enriched uranium, marking the coming into force of an interim deal with world powers on its disputed nuclear programme. AFP PHOTO/IRNA/KAZEM GHANE (Photo by KAZEM GHANE / IRNA / AFP) (Photo by KAZEM GHANE/IRNA/AFP via Getty Images)