A team of 14 UN inspectors arrived in Kiev prior to their visit to the Zaporozhye nuclear power plant (NPP) in southeastern Ukraine later this week, in light of mounting fears over a potential nuclear accident.

Members of the International Atomic Energy Agency (IAEA) delegation were spotted at their hotel in Kiev early Tuesday, CNN reported.

International Atomic Energy Agency (IAEA) chief Rafael Grossi said Monday that the Agency's inspectors are on their way to the Zaporozhye NPP power plant amid mounting fears over a potential nuclear accident.

"The day has come, IAEA's Support and Assistance Mission to Zaporozhye is now on its way," Grossi tweeted.

He affirmed the team from the UN atomic watchdog would arrive at Europe's largest nuclear power plant "later this week".

The IAEA's announcement comes as Russia's Defense Ministry warned Saturday that the site of the Zaporozhye NPP was shelled repeatedly over the past 24 hours.

On his account, the head of the regional military-civil administration Yevhen Balytskyi affirmed that Zaporozhye city authorities have expressed readiness to facilitate IAEA experts’ visit to ZNPP and provide them with security, as per Sputnik.

"We are ready to receive an IAEA mission, we are ready to provide them with full security on our part, we are ready to provide them with access to the station and the adjacent territory so that they can assess the real situation, inspect the shelling sites and get proof that shelling is carried out from the territory controlled by Ukraine… The main question is whether Ukraine is ready to adhere to a ceasefire for the duration of the mission," Balytskyi said.

However, he also expressed doubts that Kiev would allow the IAEA to visit the Zaporozhye nuclear power plant.

"Ukraine is doing everything to prevent the IAEA mission from entering the station," Balitsky said.

"I think the Kiev regime will do everything, find any excuse, to prevent the IAEA representatives from coming. This visit is not beneficial for Ukraine," he stressed.

On Sunday, the Russian Ministry of Defense once again warned that Ukraine continues with its "provocations aimed at creating a threat of a man-made nuclear disaster" at the Zaporozhye NPP power plant. 

US official: Ukrainian nationals behind attack on ZNPP

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."

What you need to know

Russian forces have had complete control over the Zaporozhye NPP 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.

Two weeks ago, Russia accused the office of the United Nations Secretary-General of obstructing the work of IAEA experts and preventing them from visiting the NPP in eastern Ukraine.

Moscow had underlined several times that a trip by an IAEA delegation to the NPP through Kiev and then across the contact line will be very dangerous.

It is noteworthy that according to the head of the Russian National Defense Control Center, Colonel General Mikhail Mizintsev, the Russian Defense Ministry is considering the shelling of the Zaporozhye NPP by Ukrainian forces an act of nuclear terrorism under a UN convention adopted by a resolution of the UN General Assembly. 

The official said if an accident were to happen, which the shelling could potentially cause, the effects would surpass the scale of Chernobyl and Fukushima - the entire territories of Ukraine, Donetsk, Lugansk, Russia, Belarus, Moldova, Bulgaria, and Romania would be contaminated by nuclear waste.

According to the Russian Defense Ministry, the Ukrainian army sabotaged a high-voltage power line that provides electricity to nearby regions, which sparked a "power surge" at the station, causing smoke in a switchgear used to protect electrical equipment. 

Russia has rejected previous claims, made by US Secretary of State Antony Blinken, that it uses the Zaporozhye NPP as a military base.