Ukrainian President Volodymyr Zelensky posted on Telegram that there had been more than 140 attacks on Ukrainian positions in the first few hours of the truce, and more than 850 drone strikes.

“All of this clearly indicates that there was not even a simulated attempt from the Russian side to cease fire at the front,” he said.

“Just like in the results of the past day, Ukraine will act in kind today.”

On Thursday Ukraine accused Russia of breaching Kyiv’s unilateral ceasefire, launching drone attacks, including on a kindergarten in Sumy region. Two people were killed in that attack, although no children were present at the time.

The war of words over ceasefires came after European Council President António Costa said he thought there was “potential” for the EU to negotiate with Russia over ending the war, and said they had Zelensky’s backing to do so.

“I’m talking with the [EU’s] 27 national leaders to see the best way to organise ourselves and to identify what we need effectively to discuss with Russia when it comes to the right moment to do this,” he said in an interview with the Financial Times on Thursday.

“We cannot change the geography. We are in Europe, we are neighbours of Russia, and of course we need to talk with them about the future of the security architecture of Europe,” he added.

Kremlin spokesman Dmitry Peskov responded that Russia was ready for dialogue but “will not initiate such contacts ourselves”.

The US has mediated several rounds of talks between Russia and Ukraine but so far without any breakthrough, and there are concerns that Washington is now distracted by the war in the Middle East.