VIENNA, June 20 (Xinhua) -- The Bushehr Nuclear Power Plant is the Iranian nuclear site where the consequences of an attack could be most severe, the United Nations nuclear watchdog chief warned on Friday.

Rafael Grossi, director general of the International Atomic Energy Agency (IAEA), made the remarks during a UN Security Council session via video link, noting that countries in the region had contacted him over the past few hours to express deep concern.

Grossi emphasized that a direct hit on the plant could result in a significant release of radioactivity into the environment. Bushehr is an operational facility housing thousands of kilograms of nuclear material. A strike disabling its only two power lines could lead to a meltdown of the reactor's core, similarly causing a major radioactive release, he explained.

He warned that in worst-case scenarios, protective actions such as evacuation, sheltering, or the use of stable iodine could be required, with impacts potentially reaching several hundred kilometres. Radiation monitoring and food restrictions might also be necessary across wide areas.

Grossi also raised concerns about the Tehran Nuclear Research Reactor, saying that any attack on the facility could have severe consequences for the city and its population, requiring urgent protective measures.

He pledged to continue providing public updates on the nuclear sites and their potential health and environmental risks. ■