Ukrainian President, Volodymyr Zelenskyy has accused Russia of engaging in “nuclear terrorism” as he commemorated the 40th anniversary of the Chornobyl reactor disaster on Sunday.

Zelensky stated that Russia is “once again bringing the world to the edge of a man-made catastrophe”.

He noted that Russian drones frequently fly over Chornobyl, with one having struck its protective shell last year.

Rafael Grossi, the director general of the International Atomic Energy Agency (IAEA), shared Zelenskyy’s apprehensions regarding Chornobyl during his visit to Kyiv, emphasizing that repairs to the plant’s damaged outer protective shell must commence without delay.

He remarked that “IAEA evaluations indicate that the damage incurred from a strike last year has already jeopardized a crucial safety function of the structure.”

He cautioned that prolonged inaction could increase the risk to the original sarcophagus beneath it. The European Bank for Reconstruction and Development indicated that repairs would necessitate a minimum of 500 million euros ($586 million).

In the meantime, Ukrainian forces have targeted an oil refinery in Yaroslavl, deep within Russian territory, as reported by Ukraine’s General Staff on Sunday.

The strikes ignited fires at the facility, which processes 15 million tons of oil annually and produces gasoline, diesel, and jet fuel for the Russian military.

Russia did not provide an immediate response. Ukraine has developed its own long-range drones capable of reaching targets 1,500 kilometers (900 miles) inside Russia.

Additionally, a Ukrainian drone strike also impacted a fertilizer plant in Russia’s Vologda region, as stated by local governor Georgy Filimonov on Sunday. Filimonov reported that a high-pressure sulfuric acid pipeline was damaged at a complex operated by Apatit, a subsidiary of PhosAgro, one of the largest producers of phosphate-based fertilizers globally.

The leak has been contained, and there were no hazardous chemical releases, he added, noting that five individuals sustained injuries.

The President of the United States, Donald Trump, mentioned on Sunday that he has had “productive discussions” with Vladimir Putin and Zelenskyy as he seeks to resolve the conflict in Ukraine.

“We’re working on the Russia situation, Russia and Ukraine, and hopefully we’re going to get it,” Trump said in an interview on Fox News.

Ukrainian peace talks have stalled since the US and Israel launched attacks on Iran on 28 February.