Unsubstantiated Russian claims that Ukraine intends to use a radiological weapon and continued shelling around Europe’s largest nuclear plant have ratcheted up concerns of nuclear escalation

The head of the United Nation’s nuclear watchdog said he hopes to “cool off” the nuclear saber rattling between Russia and the West by dispatching inspectors to the Ukrainian nuclear sites that Moscow claims are being used to divert radioactive materials for use in a “dirty bomb.”

The upcoming visit, overseen by International Atomic Energy Agency Director General Rafael Grossi, could help disprove Russia’s widely criticized claims of a Ukrainian nuclear plot. But by taking Moscow’s accusations at face value, it also risks elevating the sensational charges.

The visit will be the latest high-wire act of a bureaucrat who has conversed extensively with Russian President Vladimir Putin and Ukrainian President Volodymyr Zelensky while trying to maintain his agency’s status as a neutral watchdog of the world’s most dangerous materials.

Grossi, speaking to reporters during a visit to The Washington Post on Tuesday, emphasized Ukraine’s support for the inspection and said the visit can provide clarity to a heated international dispute.

“It required a formal invitation [from Ukraine],” Grossi said. “I decided that it was, of course, my duty to step forward.”

The two sites the IAEA plans to inspect are a research facility that produces isotopes and a mine that can process uranium. The goal is to ensure that nothing has gone missing.

Grossi said he is “so far” unaware of any missing radioactive material in Ukraine, but he is seeking to quickly dispatch inspectors to Ukraine to check inventories against the agency’s existing records. Putin on Wednesday repeated the accusation that Ukraine was planning to build and use a dirty bomb, drawing from its civilian stores of uranium and other radioactive material.