In an event that could take the course of the war in Ukraine to a new turn , officials in Kiev have warned that Russia has booby-trapped a huge hydroelectric dam in southern Ukraine, which portends the possibility of a "large-scale disaster."

The head of the Ukrainian presidential office, Andriy Yermak, said on Friday evening that Moscow's "nuclear blackmail" had failed, adding that the Kremlin was "now resorting to new methods of intimidation".

"Ukraine will not surrender to peace under duress," he added, stressing that "they will not break us. We will respond more forcefully ".

For his part, Ukrainian prime minister Denis shmigal said at a cabinet meeting: "we call on the United Nations, the European Union and other organizations to organize an international observation mission to the kakhovka dam. International experts should arrive immediately (to the site), as well as a Ukrainian crew,"he said.

Shmigal stressed that the possibility of an explosion of the dam of a hydroelectric power station "could leave thousands of victims and cause flooding of dozens of villages".

On Thursday evening, Ukrainian President Volodymyr Zelensky accused the Russians of booby-trapping the dam located in the Kherson region, controlled by Moscow's troops.

Zelensky warned that "in case the dam is destroyed (...) The northern Crimean canal will simply disappear", and this will be a "large-scale disaster".

Also, on Thursday, he told the European Union that "more than eighty towns, including Kherson, are in the flash flood zone".

For its part, the Russian authorities in Kherson denied any booby-trapping of the dam, denouncing the" lies " peddled by Zelensky