Ukrainian Foreign Minister Dmytro Kuleba began an official visit to Serbia on Monday, where the new premier vowed support for Ukraine's "territorial integrity" in the face of the Russian invasion.

Serbia remains a rare outlier in Europe for refusing to sanction the Kremlin following Russia's full-scale invasion of its neighbor in February 2022.

Kuleba's visit was his first to the Balkan country since the outbreak of the conflict. 

Kuleba met President Aleksandar Vucic, Prime Minister Milos Vucevic and several other top government figures. 

"Prime minister Vucevic stressed that Serbia is committed to respecting international law and the territorial integrity of each United Nations member state, including Ukraine," the Serbian government said in a statement. 

Belgrade has long been close to Moscow. 

Its shared Orthodox heritage, mutual distrust of NATO and military alliances throughout several wars have strengthened their ties.

Since early 2022, Serbia has welcomed tens of thousands of Russians fleeing to avoid being sent to the front. 

President Vucic has already met Ukrainian leader Volodymyr Zelensky several times, including for a brief sit down during a summit in Albania in late February. 

Ukrainian First Lady Olena Zelenska was also in the Serbian capital Belgrade on Monday to sign a partnership with a university in Serbia, according to a post on X, and meet representatives of the Ukrainian community in the Balkan country. 

The visit came less than a week after Serbia rolled out the red carpet for Chinese President Xi Jinping during his three-country European tour. 

Serbia has long walked a fine line on the diplomatic front.

It has simultaneously sought to join the European Union, welcomed Chinese investment and remained on largely friendly terms with the Kremlin. 

It has been reliant for years on support from both Russia and China to prevent the UN from recognising Kosovo as independent, following its secession from Serbia in 2008.

Ukraine has never recognised Kosovo's unilateral declaration of independence either.

Russia on Monday pummelled more than 30 towns and villages in Ukraine's northeastern Kharkiv region after launching a surprise ground offensive over the border last week.