It would be a “fatal mistake” for any country to assume it will not be hit by the new coronavirus, and rich countries that might have thought they were safer should expect surprises, the head of the World Health Organization said on Thursday.

The head of the WHO’s emergency program said Iran, which has so far reported the most deaths outside of China, may be dealing with an outbreak that is worse than yet understood. He also said discussions were being held with organizers about the fate of the Olympic games scheduled for July in Japan.