A senior US military official acknowledged Monday that Ukrainian forces may have been behind the attack in the vicinity of the Zaporozhye Nuclear Power Plant (ZNPP), but claimed that this was solely in reaction to alleged Russian fire that came from the region. The roof of the structure housing reactor fuel was allegedly destroyed by an artillery round fired by Ukraine earlier in the day, according to Russian authorities.

The Ukrainian troops, upon shelling the ZNPP, on August 29, tore through the roof of the special building where the fuel for the nuclear reactor is stored, breaking it as a result of the aggression, according to Vladimir Rogov, a member of the main council of the Zaporozhye region military-civil administration. 

A US official giving a background briefing at the Pentagon said "I -- so what I know for sure is that the -- the Russians are firing from around the plant and, you know, I also know that there are rounds that have impacted near the plant. You know, the way that we're tracking the forces around the nuclear power plant -- it's not like there's a -- a constant -- it's hard to explain, I guess. It's not like there are forces in every square inch of the area around the plant. And so we also know that the Russians have fired in the vicinity of the plant."

Following the confusing statement, the official also added that "I don't want to say that the Ukrainians haven't fired in that vicinity either because I think there's probably a likelihood that they have."

The physical damages sustained on the facilities will be assessed by the International Atomic Energy Agency (IAEA) mission upon arrival, where they will also determine the operability of the main and backup security and safety systems, according to the organization in a statement. 

IAEA Director General Rafael Grossi early on Monday said that the IAEA mission is already heading to the ZNPP and will be arriving on site this week. 

"Once reaching [Zaporozhye] later this week, ISAMZ will assess the physical damage to the facilities, determine the functionality of the main and backup safety and security systems, and evaluate the working conditions of the control room staff. At the same time, the mission will undertake urgent safeguards activities to verify that nuclear material is used only for peaceful purposes," the statement says.

Russian forces have had complete control over the ZNPP since March, but drone attacks by Ukrainian forces have regularly targeted the facility, leading Russia to request help from the IAEA to address security issues.

Read more: IAEA may prop up permanent post at Zaporozhye NPP: Chief