'We will win this war'
Ukrainian President Petro Poroshenko promised to defeat the "cruel-hearted foe" trying to break his former Soviet republic apart, in a traditional New Year's message.
The pro-Western leader delivered the midnight television address surrounded by soldiers and volunteers who handed out food during protests last winter that ousted an unpopular Russia-backed president.
"A cruel-hearted foe has encroached on our lives, territory, freedom and independence," said Poroshenko, without mentioning Russia or President Vladimir Putin by name.
"We will definitely win this patriotic war because for us, it is just. Truth is on our side. God is with us."
The 49-year-old chocolate baron won a snap election in May on a promise to stamp out the pro-Russian mutiny that erupted in Ukraine's industrial east in April and has since claimed more than 4,700 lives.
A truce brokered by Russian and European envoys in September has been repeatedly broken and new talks aimed at consolidating that agreement broke up without progress last week.
Relations between Kiev and Moscow -- accused by both Poroshenko and NATO of supporting the rebel uprising -- are now more hostile than at any point since the 1991 breakup of the USSR.
Poroshenko's name was notably missing from the dozens of New Year congratulatory messages that Putin sent out to world leaders on Wednesday.