Vucic, who met the Ukrainian leader at a summit of southeastern European countries in Albania, offered further humanitarian help and said he believed "only constructive dialogue and diplomatic solutions can bring peace".

Writing on Instagram, he also thanked Ukraine for being one of a handful of countries to refrain from recognising Serbia's breakaway province of Kosovo.

Zelenskiy, writing on X, formerly Twitter, "noted the importance of Serbia's participation" in implementing Ukraine's plan, which calls for withdrawal of Russian troops and the restoration of Ukraine's 1991 post-Soviet borders.

He said the two leaders also discussed "security and political challenges in Eastern Europe".

Last year, a classified Pentagon document said Serbia had agreed to supply arms to Kyiv or had sent them already, despite its professed neutrality in the Ukraine war. Serbia has refused to sanction Russia, with which it has traditional ties.

In his comments, Vucic said one had to keep in mind Serbia's Slav links with Ukraine. Ukraine's refusal to recognise Kosovo, he said, made it "one of the few countries that can talk about territorial integrity, because it did not trample on someone else's territorial integrity, like most others".

Ukraine refused to recognise the independence of Kosovo from Serbia, proclaimed in 2008, as it has long had to deal with separatist movements, before the outbreak of the current conflict, in Crimea and in the east of the country.

(Reporting by Ron Popeski and Aleksandar Vasovic; Editing by Sandra Maler)