The Volhynia massacre, in which the Ukrainian Insurgent Army ethnically cleansed Poles in what is now western Ukraine during the Second World War, has come to haunt Polish-Ukrainian relations.
The Volhynia massacre, which took place in 1943-1944 and resulted in the deaths of tens of thousands of Poles, remains highly controversial, with experts still debating whether it can be described as genocide.
But when Ukrainian Foreign Minister Dmytro Kuleba was asked whether Kyiv would allow exhumations of the victims - a longstanding demand from Warsaw - during an event organised as part of the National Day of Remembrance for the Victims of Genocide, which Poland has commemorated since 2016, he replied vaguely.
He said historical issues like the Volhynia massacre should be left to historians so that the focus can shift to building a shared future - this was met with widespread criticism in Poland, where the minister's statement was received as disrespectful.
Although Deputy Prime Minister and Defence Minister Władysław Kosiniak-Kamysz (Polish People's Party, EPP) and Prime Minister Donald Tusk (KO, EPP) have both stressed that Ukraine's EU membership depends on properly addressing and commemorating Polish victims and resolving historical disputes with Poland, Kosiniak-Kamysz spoke again about the dispute in an interview with Polish public radio on Friday.
Ukraine should take care to fulfil Poland's demands related to historical crimes committed by the Ukrainian Insurgent Army (UPA), Kosiniak-Kamysz said, adding that Kyiv’s EU future depended on Warsaw.
In addition to warning Ukraine that the dispute needed to be resolved for EU membership talks to proceed, Kosiniak-Kamysz added that Poland had already done much to support Ukraine in the midst of its war with Russia, and while it would continue to help, Ukraine should appreciate Poland's efforts.
He also ruled out sending additional MIG-29 fighter jets requested by Ukraine, saying they were needed to protect Polish airspace.
Foreign Minister Radosław Sikorski (KO, EPP) joined the chorus of criticism on Tuesday, advising Ukraine to ensure the request for exhumations in Volhynia is carried out.
“Ukraine, of course, also has certain demands on us. But Poland will decide to close the next chapters of Ukraine's negotiations with the European Union, so it is better for Ukraine to settle this matter as soon as possible,” he told public broadcaster TVP Info.
Poland has been one of Ukraine's staunchest supporters since the first day of the full-scale Russian invasion, and while it remains so, more and more issues are emerging that are causing bad blood between the two countries.
One issue that has yet to be fully resolved is the influx of Ukrainian agri-food products onto the Polish market since 2022, thanks to the so-called solidarity corridors opened by the EU to facilitate Ukrainian exports.
The influx has caused significant problems for Polish domestic production and was the main reason for farmers' protests earlier this year.
(Aleksandra Krzysztoszek | Euractiv.pl)