With Chernobyl and Fukushima in recent memory, the global community is desperate to prevent another nuclear disaster.

International inspectors were heading Monday to the Ukrainian nuclear plant at the center of growing alarm about a potential radiation disaster.

The United Nations nuclear watchdog mission is set to arrive at the Russian-occupied Zaporizhzhia power plant later this week, offering hope for progress even as the two warring sides exchanged new accusations of shelling around the complex in southern Ukraine.

“The day has come,” Rafael Grossi, the head of the U.N.’s International Atomic Energy Agency, said in a tweet early Monday, announcing that a team was “on its way” after weeks of negotiations about getting nuclear inspectors access to the site near the conflict’s front lines. 

“We must protect the safety and security of Ukraine’s and Europe’s biggest nuclear facility,” he said.

The mission, which will be led by Grossi, will assess physical damage to the plant, determine how well its safety systems are functioning, evaluate working conditions for its staff and perform any urgent safeguard activities, the IAEA said in a separate tweet.

The U.N.’s atomic energy agency has warned for months about the risk of a nuclear catastrophe, and has sought to send in a team to inspect and help secure the safety of the plant. 

Kremlin spokesman Dmitry Peskov said Monday that Moscow considers the mission necessary, the Russian state news agency Tass reported.

He was quoted as saying that Russia will ensure the safety of the IAEA inspectors on the territory that it controls, but reiterated Moscow’s opposition to creating a demilitarized zone around the plant. It’s up to the international community to pressure Kyiv to reduce tensions around the site, he added.

Earlier, Mikhail Ulyanov, the Russian envoy to international organizations in Vienna, told the state news agency Ria that the mission consists of about 15 people and some of its members will stay behind at the plant on a permanent basis.

“We hope that the visit of the station by the IAEA mission will dispel numerous speculations about the unfavorable state of affairs” at the plant, he was quoted as saying.

NBC News has reached out to the IAEA for comment on the claim.

Ukrainian Foreign Minister Dmytro Kuleba said Monday that the mission “will be the hardest in the history of IAEA” given the active fighting on the ground.

Last week, fighting in the area temporarily disconnected the plant from Ukraine’s power grid for the first time in its 40-year history, with President Volodymyr Zelenskyy saying the incident left the world narrowly avoiding a radiation catastrophe.