"We still don't know 100 percent of the exact circumstances and reasons for the Przewodow incident, but we definitely know the root cause — the main reason — and that is the Russian aggression against Ukraine," Polish Prime Minister Mateusz Morawiecki said.

During a massive nationwide Russian attack against Ukraine on Nov. 15, a blast killed two people in the Polish village of Przewodow, about six kilometers west of the Ukrainian border.

The next day, President Volodymyr Zelensky denied claims by NATO and Poland that a Ukrainian missile had likely landed on Polish territory.

National Security and Defense Council Secretary Oleksiy Danilov said Ukraine is "ready to hand over evidence of the Russian trace" in the accident.

At the same time, NATO Secretary General Jens Stoltenberg said that the investigation into the blast is ongoing, but there was "no indication that Russia is preparing offensive military actions against NATO."

On Nov. 17, Foreign Minister Dmytro Kuleba and his Polish counterpart Zbigniew Rau discussed a joint investigation of the Przewodow incident.