This is the first death since the new ceasefire established last month by the belligerents, in a conflict that has claimed more than 13,000 lives since 2014.
A soldier was fatally injuredthe Ukrainian army said in a statement, accusing the separatists of carrying out three attacks in the past 24 hours.
Ukraine has been at war since 2014 against pro-Russian separatists who control parts of the territory in the east of the country and who are, according to Kiev and the West, financially and militarily supported by Moscow.
On December 22, the belligerents agreed to restore a ceasefire on the front line, before accusing themselves of new violations the next day. All previous truce attempts have failed.
Relations between Ukraine and Russia, already very tense in recent years, are currently experiencing a peak of tension.
For more than a month, Russia has been accused by the West of having massed tens of thousands of soldiers near the Ukrainian border, with a view to a possible military intervention against Kiev.
Moscow denies any bellicose intention and claims to be threatened by
Provocation from Kiev and NATO, and demands that the Alliance undertake not to expand into the former USSR.
These demands are to be addressed in Russian-US negotiations in January.
US President Joe Biden is also due to speak with his Ukrainian counterpart Volodymyr Zelensky over the phone on Sunday.
In his televised address to Ukrainians on the occasion of the New Year, Zelensky assured that ending the war in the East remains his