Ukrainian leader Volodymyr Zelenskyy has returned Poland's highest state honor, after the Polish president stripped him of the award as a politically charged dispute over World War II history resurfaced.

Ukrainians believed the order "was meant for the Ukrainian People and our army," Zelenskyy wrote in a social media post explaining the gesture. "Today, I sent the Order back to the President of Poland. I believe the future will confirm the respect Ukrainians deserve."

The message published on X is accompanied by photos of the Polish order and a postal receipt that it was about to be mailed to the Polish presidential office.

President Karol Nawrocki decided to strip Zelenskyy of the Order of the White Eagle over the Ukrainian leader's decision to name a military unit after a Ukrainian paramilitary organization accused of massacring Poles during WWII.

Former Polish President Andrzej Duda bestowed the award on Zelenskyy in 2023 for services to security, resilience and the defense of human rights.

Zelenskyy issued a decree on May 26 naming a unit of Ukraine's Special Operations Forces after the Ukrainian Insurgent Army, or UPA, which operated during the 1940s and 1950s and has been accused in Poland of mass killings.

"For the majority of Polish society, the Ukrainian Insurgent Army remains above all a formation responsible for cruel crimes against the citizens of the Polish Republic during World War II," Nawrocki said in a 13-minute address on social media.

The Ukrainian decree was met with widespread criticism in Poland, which has hosted millions of Ukrainian refugees and is a key supporter of Kyiv as it battled Russia's four-year invasion. However, Nawrocki is a nationalist politician who has exploited anti-Ukrainian sentiment for electoral gain. Ukrainians in Poland have been facing increasing prejudice despite their contribution to the economy.

The decision to revoke the honor did not mean Poland's support for Ukraine in its defense against Russia would decrease, Nawrocki said.

Ukraine is grateful to Poland for its support, and would stay open to resolve historical differences with Poland, Zelenskyy wrote Saturday in his post. "I am proud of our people and of EVERY Ukrainian warrior."

Ukrainian Presidential Office chief Kyrylo Budanov wrote on Telegram that Nawrocki's decision was "an unfriendly act toward our people" and "a gift to the Moscow aggressor, which will certainly use it against both of our countries."

Four Ukrainian officials, including Budanov, said they would return state honors that Poland had issued them.

Some in Ukraine criticized the decision to return the Polish honors.

Arseniy Yatsenyuk, Ukraine's former prime minister, wrote on X that one "harmful and incorrect decision by the current president of Poland cannot be corrected by other incorrect decisions of ours."

Poland is scheduled to host a major event on Ukraine's postwar reconstruction next week, which Zelenskyy was expected to attend.

Polish Prime Minister Donald Tusk, a political rival of Nawrocki, urged the two leaders to "tone down emotions, not stoke tensions."

"The front line runs elsewhere," Tusk wrote on social media Friday night, adding that the row between Poland and Ukraine "delights Putin and shocks our allies."

Zelenskyy's May decree said the designation was meant to restore military traditions and recognize the unit's performance in defending Ukraine's territorial integrity and independence.

The UPA fought for Ukrainian independence against both Nazi Germany and Soviet forces. But it has been accused of killing tens of thousands of Poles, mostly in the Nazi-occupied regions of Volhynia and Eastern Galicia. In 2016, the Polish Parliament recognized the crimes committed by UPA as genocide.

Ukrainians say armed formations on both sides, including the UPA and Polish underground forces, were involved in attacks and reprisals that led to large-scale civilian casualties among Poles and Ukrainians.

Poland and Ukraine had recently made progress on the issue of exhumation of Polish victims. A December meeting between the two presidents in Warsaw had signaled progress on historical reconciliation.