KYIV, - Ukrainian President Volodymyr Zelenskiy said on Saturday he had returned a state decoration a day after Poland 's president said he had stripped him of the award in connection with a dispute over events in World War Two.Polish President Karol Karol Nawrocki said on Friday he had revoked the medal awarded to Zelenskiy in 2023 after the Ukrainian president renamed a military unit in honour of World War Two-era Ukrainian insurgents accused ‌of massacring Poles.The ⁠row ⁠over the role of the Ukrainian Insurgent Army (UPA) threatens to deepen a diplomatic rift between the close strategic partners as Kyiv rallies allies to push Russia to end its war on Ukraine."We believed that the Order of the White Eagle, awarded in 2023, was meant for the Ukrainian People and our army. That is what was said at the time," Zelenskiy wrote on X. "Today, I sent the Order back to the President of Poland."Zelenskiy posted a photo ​of the decoration being packed in a box and being sent ⁠to the ‌Polish president's office.He said Ukraine was grateful for Poland's support and pledged Kyiv ​would "remain open to ​all meaningful formats of engagement with Poland in order to try to avoid ⁠conflicting interpretations of the difficult and painful chapters of our shared past".Zelenskiy's chief ​of staff, Kyrylo Budanov, said he was renouncing the Golden Officer's Cross of ​the Order of Merit of the Republic of Poland, awarded to him last year, to protest against a move he described as "a gift" for Russia.Ukrainian Foreign Minister Andrii Sybiha had earlier called Nawrocki's decision a "strategic error" and said no president of a foreign country "is going to dictate our history to us". Polish Prime Minister Donald Tusk, an opponent of Nawrocki, urged both leaders to remain calm.In announcing his decision to ‌revoke the award to the Ukrainian president, Nawrocki said the move was "not directed against the Ukrainian people. It does not signify a change in the strategic direction of Polish ​security policy."Warsaw is ​a strong supporter of ⁠Kyiv in the more than four-year-old conflict with Russia. But public sentiment towards Ukraine has become more negative in recent years due to weariness with large numbers of refugees, disputes over grain imports and the legacy of ​the World War Two massacres.Some Ukrainians regard the UPA as heroes for the resistance they mounted against both the Soviet Union and Nazi Germany, and as symbols of Kyiv's struggle for independence from Moscow.But the UPA was also involved in the Volhynia massacres, a series of killings from 1943 to 1945 in which Poland says around 100,000 Poles were killed by Ukrainian nationalists. Thousands of Ukrainians also died in reprisal killings.