Ukraine's Volodymyr Zelensky has been stripped of Poland's highest state honour, the Order of the White Eagle, over Kyiv's decision to name a military unit after controversial World War Two fighters.

Polish President Karol Nawrocki branded Ukraine's decision late last month to name the unit after the Ukrainian Insurgent Army (UPA) "outrageous", "incomprehensible" and "deeply disappointing".

Nawrocki stressed the diplomatic row would not impact Poland's support for Ukraine against Russia.

Ukraine's Foreign Minister Andrii Sybiha denounced Warsaw's move, calling it a "strategic mistake" and "disrespectful".

Many in Ukraine regard the UPA, which existed in the 1940s and 1950s, as heroes who fought for Ukrainian independence against the Soviet Red Army as well as Nazi Germany and Polish authorities. So for Ukrainians the title "Heroes of the Ukrainian Insurgent Army" is a major honour.

Poland, however, accuses the UPA of carrying out a genocide of ethnic Poles in Volhynia (now Volyn in Ukraine) in 1943-45.

"For the overwhelming majority of Polish society, the UPA remains, above all, a formation responsible for the brutal crimes committed against citizens of the Republic of Poland during World War II," Nawrocki said in a video released on the president's official website.

"That is why the Ukrainian authorities' decision to glorify the UPA is not only outrageous, it is also incomprehensible and deeply disappointing," he said.

"It hurts not only our historical memory. It also undermines the trust built up over the years and in recent months," he added.

The Polish president pointed to the hundreds of thousands of Ukrainian refugees welcomed into the country following the launch of Russia's full-scale invasion in 2022.

"Poles opened their borders, their homes, and their hearts to millions of Ukrainians," he said.

He went on to say: "Ukraine's path toward European structures also requires a willingness to honestly confront the difficult chapters of its own history.

"A united Europe was built on the rejection of totalitarianism and the cult of violence. These principles must apply to everyone. For those who do not understand this, there can be no place in the European Union, and Poland will certainly not allow it."

Ukraine has ambitions to become an EU member state and attended the first phase of membership negotiations this week in Luxembourg.

For Ukraine, the UPA is a symbol of resistance and struggle for independence, even though Warsaw says about 100,000 ethnic Poles were killed in the Volhynia massacres.

The group's red and black flag is often used by Ukrainian troops on the front line today. That's why Zelensky said he would use the UPA's name for a military unit, "with the aim of restoring the historical traditions of the national army".

The Polish Order of the White Eagle was bestowed on Zelensky in 2023 by then-President Andrzej Duda.

Zelensky himself has not directly commented on the row. But Sybiha called it "a strategic mistake by the President of Poland, from which only Moscow benefits".

He said as a result of the announcement, he would be returning an award he received from Poland in 2022.

"No president of another country will dictate our history to us," he said.