Serbian President Aleksandar Vucic apologised on Monday to citizens after Serbia voted for a UN resolution on Ukraine, saying it was a mistake.

''I think Serbia made a mistake today. I apologise to the citizens for that, and I bear the blame for it myself because I guess I'm tired and burdened and I can't get everything done," Vucic said on a live programme on Happy TV.

He said Serbia should have abstained from voting for the European resolution as it did for an American one.

"As far as the American resolution is concerned, we voted exactly as it should have been. We abstained. We should have abstained, in my opinion, from the European resolution as well. As you can see, I am saying this at a time when it is quite clear that I will lose favour or political points in the EU because of this. I believe that Serbia had to abstain," said Vucic.

Vucic said he believes Serbia should not flatter Russia or the US but that it would be in its best interest to abstain.

The UN General Assembly adopted a draft resolution Monday calling for a just and lasting peace in Ukraine, with Russia and the US voting against it.

The resolution passed with 93 votes in favour, 18 against and 65 abstentions.

Proposed by Ukraine and European nations, it highlighted the global impact of Russia's now over three-year war on Ukraine and raised concerns over reports of North Korean troops fighting alongside Russia.

It urged an immediate cessation of hostilities, reaffirmed calls for Russia's full withdrawal and emphasised diplomatic efforts to prevent further escalation.