KYIV, June 20 - President Volodymyr Zelenskiy's chief of staff said on Saturday he was renouncing a Polish state medal after President Karol Nawrocki stripped Zelenskiy of Poland's top honour over a historical dispute.

The move by Kyrylo Budanov threatens to deepen a diplomatic rift between the close strategic partners as Kyiv rallies allies to push Russia to end its war on Ukraine.

Nawrocki said on Friday he was revoking the Order of the White Eagle from Zelenskiy after he renamed a military unit in honour of World War Two-era Ukrainian insurgents blamed for massacring Poles.

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.

"Our nations have long-standing relations and different pages of history - both heroic and tragic," he posted on social media. "However, this should be an occasion for deep reflection, not crude political speculation."

Ukrainian Foreign Minister Andrii Sybiha had earlier called Nawrocki's decision a "strategic error", and Polish Prime Minister Donald Tusk, a Nawrocki opponent, urged both leaders to remain calm. REUTERS

Zelenskiy's chief of staff renounces Polish medal amid WW2 dispute