President Volodymyr Zelensky has promised a sharp increase in the amount of weapons Ukraine produces next year.
In his new year's message, Mr Zelensky repeated his pledge that at least a million drones would be built.
There was more fighting overnight into New Year's Day with five people killed in attacks in Odesa in Ukraine's south, and the Russian-held Donetsk region.
Earlier Vladimir Putin gave his new year address, praising his army but without explicitly mentioning the war.
The Russian president hailed his soldiers as "heroes... at the forefront of the fight for truth" and also referenced economic issues, a key topic for many Russians, and declared 2024 the "year of the family".
Speaking on Sunday, as the war against Russia approaches its third year, Mr Zelensky said: "Next year, the enemy will feel the wrath of domestic production."
He said Ukraine would produce "a million" extra drones in 2024 - something he said earlier this month - and that F-16 fighter jets would be delivered by Ukraine's Western partners.
"Our pilots are already mastering F-16 jets, and we will definitely see them in our skies," he said. "So that our enemies can certainly see what our real wrath is."
The new year's message came just hours before more attacks. In Donetsk, which is occupied by Russia, four people were reported killed and 13 wounded, according to Denis Pushilin, the Russian-installed head of Donetsk, on Telegram.
He described the attack as "massive shelling from multiple launch rocket systems".
Separately in Odesa, in the south of Ukraine, one person was killed and three others were wounded in a Russian drone attack, local governor Oleg Kiper said.
Fighting has escalated in recent days, after Russia carried out strikes across Ukraine on Friday, killing 39 people in what Kyiv described as Russia's biggest missile bombardment of the war so far. Several cities were hit, including the capital, Kyiv.
This was followed by Ukrainian attacks on Russia on Saturday, with Moscow reporting deadly air strikes on the south-west of the country - with 24 people killed and more than 100 injured in Belgorod, near the border.
Mr Zelensky urged his Western allies to keep up support for Ukraine, as the country faces the prospect of a slowdown in aid from allies in Washington and Europe.
Ukraine has received its last package of military aid from the US - with any further aid packages being held up by a row in US Congress.
Mr Zelensky has admitted his country's spring offensive has not been the success he hoped, but in his message insisted that his country had become stronger in the face of Russia's full-scale invasion.
Mr Putin did not broach the war in Ukraine during his new year address, which was noticeably scaled back compared to last year's.
But he said: "To everyone who is at a combat post, at the forefront of the fight for truth and justice: You are our heroes, our hearts are with you," he said. "We are proud of you, we admire your courage."
