UKRAINIAN President Volodymyr Zelensky said today that an all-out war with Russia was a possibility as relations between the two nations remain fraught.

He was speaking at the Yalta European Strategy (Yes) summit when he was asked whether the tensions could escalate into a fully fledged conflict.

“I think there can be,” he said, adding: “This is the worst thing that there can be, but unfortunately there is such a possibility.”

Mr Zelensky nonetheless said that such a war would be “the greatest mistake,” warning: “After that, the neighbourhoods of Russia, Ukraine and Belarus will never exist.”

The annual Yes summit, which takes place in Kiev, was established in 2004 with the aim of bringing Ukraine closer to Europe.

Relations between Moscow and Kiev have become increasingly fraught, having deteriorated after the 2014 EU-backed Maidan coup against Ukraine’s democratically elected government.

Those who came to power provoked war in Donbass by deploying the neonazi Azov battalion in the eastern region, leading to the formation of the breakaway Donetsk People’s Republic and the Luhansk People’s Republic.

In Crimea, residents voted in a 2014 referendum to federate with Russia, with some 97 per cent in favour on an 83 per cent turnout, after the Russian military had occupied the peninsula.

A summit of world leaders called by Mr Zelensky took place last month, with those present, including US and EU representatives, discussing Ukraine’s bid to regain control of Crimea.

More ominously, some 28,000 US and Nato troops have mobilised for military exercises in a dozen countries from the Balkans to the Black Sea as part of a war game dubbed Defender Europe 21.

Ukraine has described the operations as a dry run for “the war with Russia.”

Kiev has strengthened its relations with Washington, according to Mr Zelensky, but it is waiting to hear the result of its application for Nato membership.