The major step is the culmination of several festering stand-offs between the International Atomic Energy Agency and Iran.

Iran has warned it will ramp up its nuclear activities after the United Nations nuclear watchdog’s 35-member board of governors adopted a resolution Thursday declaring it in breach of its non-proliferation obligations.

The U.N. nuclear watchdog’s board of governors on Thursday formally found that Iran isn’t complying with its nuclear obligations for the first time in 20 years, a move that could lead to further tensions and set in motion an effort to restore United Nations sanctions on Tehran later this year.