The Ukrainian air force said that Russia had launched 133 drones across the country overnight -- including attack drones -- targeting northern regions of the country where the Chernobyl power plant lies.

"Last night, a Russian attack drone with a high-explosive warhead struck the cover protecting the world from radiation at the destroyed 4th power unit of the Chernobyl Nuclear Power Plant," Zelensky said in a social media post.

The comments came just hours before Zelensky was due to meet with US Vice President JD Vance in Germany to lay out Ukraine's case before a new US administration eager to quickly end the nearly three-year war.

The attack is evidence that Russian President Vladimir "Putin is definitely not preparing for negotiations -- he is preparing to continue deceiving the world", Zelensky said.

CCTV footage posted by the Ukrainian leader showed a blast on the side of the Chernobyl structure in footage that was timestamped 02:02 am (0002 GMT).

The Kremlin rejected that its army targeted Ukrainian nuclear structures.

"There is no question of any strikes on such nuclear infrastructure sites. Any claims that this was the case do not correspond to reality. The Russian military does not do this," Kremlin spokesman Dmitry Peskov said Friday, after stating that he did not have "exact information" about the reported hit on Chernobyl.

Zelensky's video also showed a small fire and hole in the roof, and firefighters using a hose to put out the blaze from the inside of the dome.

He said the drone had flown at an altitude of 85 metres (yards), too low to be detected by radar.

The International Atomic Energy Agency (IAEA) also reported an "explosion" at the site, and said "radiation levels inside and outside remain normal and stable."

The agency, which has had a team deployed at Chernobyl since the early stages of Russia's invasion of Ukraine, published images apparently showing the drone on fire after crashing into the covering.

The IAEA has repeatedly warned of the dangers of fighting around nuclear plants following Russia's full-scale military offensive into Ukraine in February 2022.

- Talks -

In the first days of the conflict, Russian forces briefly seized the Chernobyl plant and also captured the Zaporizhzhia nuclear plant in southern Ukraine, which it still controls.

In 1986, a reactor at Chernobyl exploded during a botched safety test, resulting in the world's worst nuclear accident that sent clouds of radiation across much of Europe and forced tens of thousands of people to evacuate.

Soviet authorities initially tried to cover up and then play down the disaster.

In November 2016, a massive metal dome was erected over the remains of the reactor -- paid for with 2.1 billion euros ($2.5 billion) in international funding -- to stop future leaks.

"The only country in the world that attacks such sites, occupies nuclear power plants, and wages war without any regard for the consequences is today's Russia," Zelensky added in his statement.

The Ukrainian energy ministry meanwhile "called on the IAEA to intensify efforts to prevent hostile attacks on nuclear facilities".

Russian drone and missile attacks on energy facilities throughout the conflict have crippled Ukrainian electricity generation capacity and forced routine and widespread power outages.

The apparent attack comes ahead of a series of highly-anticipated meetings at the Munich Security Conference on Friday, in which Zelensky is due to sit down with Vance.

The talks come days after US President Donald Trump stunned Kyiv and European allies by holding a lengthy telephone call with Putin and announced the two leaders had agreed to soon start Ukraine peace talks.

An advisor to Zelensky's chief of staff said that the Ukrainian delegation would be putting the Chernobyl attack on the agenda with the United States and Ukraine's allies.