"The Kremlin totally lacks credibility and this declaration of a unilateral ceasefire is not credible," European Union foreign policy chief Josep Borrell said during a visit to Morocco.
"It was Russia that launched this illegitimate aggression," he said. "When the aggressor talks of a ceasefire, I think the response that comes to us all is skepticism in the face of such hypocrisy."
The brief ceasefire declared by Russian President Vladimir Putin earlier this week was supposed to begin at 0900 GMT Friday and would have been the first full pause since Moscow's invasion in February 2022.
But artillery exchanges pounded war-scarred cities in the country's east on Friday despite Putin unilaterally ordering his forces to stop attacking for 36 hours.
AFP journalists in Bakhmut heard incoming and outgoing artillery fire for more than an hour after the 36-hour ceasefire was due to take effect on Friday, though shelling was lighter than in recent days.
The streets of the bombed-out city were mostly empty save for military vehicles.
Soldier Volodymyr Morozov told AFP he didn't even know about Putin's ceasefire call, which coincides with Orthodox Christmas on Saturday.
"This is the first time I have heard about the ceasefire -- from you," he said.
"I didn't watch the news before and I don't watch it now either. All the news I'm interested in is concerning my comrades."
EU's Borrell called for "concrete actions on the ground", including "a complete halt of military attacks".
"Russia needs to withdraw its troops and military equipment from Ukrainian territory," he said.
"In the absence of such concrete actions, a unilateral ceasefire seems to be an attempt by Russia to buy time to regroup its troops and try to repair its damaged international reputation."
Russia's invasion of Ukraine, an agricultural powerhouse, sent world food prices spiraling to their highest level on record for a full year in 2022, UN figures showed on Friday.
Borrell said Russia was using "propaganda" to blame European sanctions for the spiking food and energy prices.
"That's totally false," he said. "It's the Russian army that destroyed the grain silos, planted mines in the fields, destroyed the roads and blockaded Ukraine's ports."