According to the Director General, the IAEA mission that he expects to lead personally within a few days is intended to inspect the integrity of the Zaporozhye nuclear power plant, dialogue with Russian and Ukrainian personnel, and establish a permanent presence at the site.
The official did not specify whether the mission would access the area through Russian- or Ukrainian-controlled territory. Given the situation's urgent nature, such questions should be "put aside," Grossi said.
Ukraine has insisted the IAEA mission can only travel to the site through territory under the control of Kiev forces. In contrast, Russia has said it could only move through Russian-controlled territory.
However, Russian President Vladimir Putin agreed last week in a phone conversation with his French counterpart, Emmanuel Macron, that the mission could pass through territory currently controlled by Ukrainian forces.
Located in the southern Ukrainian city of Energodar, the Zaporozhye nuclear power plant has been controlled by Russia since March.
Russia has been asking the IAEA to inspect the site since mid-July when the plant was attacked.
The Russian Defense Ministry has denounced the risk of a radiation spill due to the Ukrainian artillery's systematic shelling of the plant. Meanwhile, Ukraine has charged Russia with shelling the nuclear site to discredit Ukraine.