Ukrainian President Volodymyr Zelenskyy denied that a Ukrainian missile accidentally landed in Poland and killed two people.

Zelenskyy told Ukrainian media that it wasn't the missile. The leader of the Ukrainians said that the country had a right to be part of the investigation.

Zelenskyy blamed Russia for the strike on the day before. As more information was gathered, western officials took a much more cautious approach.

Poland and NATO said on Wednesday that the fatal explosion was probably caused by a Ukrainian air defense missile.

"From the information that we and our allies have, it was an S-300 rocket made in the Soviet Union, an old rocket, and there is no evidence that it was launched by the Russian side," Poland's president said. It is most likely that it was fired by the Ukrainian anti-aircraft defence.

There was no evidence to suggest that it was an intentional attack, according to the man.

The NATO Secretary General said there was no indication that deaths were the result of a deliberate attack.

"We don't know if Russia is planning offensive military actions against NATO, but our preliminary analysis suggests that the incident was caused by a Ukrainian air defence missile fired to defend Ukrainian territory against Russian cruise missile attacks," said NATO Secretary General Jens Stoltenberg.

The NATO chief didn't allow Russia to off the hook.

This is not the fault ofUkraine. Russia is responsible for its illegal war against Ukraine, according to NATO Secretary-General Jens Stoltenberg.

On Wednesday, the White House agreed with the assessments.

The explosion was most likely caused by a Ukrainian air defense missile that landed in Poland, according to the National Security Council.

There were serious concerns about a direct confrontation between Russia and NATO after the explosion, but after Poland and other countries assessed that the incident was not a case of Russia attacking a NATO country, those fears have been alleviated.

There are signs that the Ukrainian government's approach to the incident could erode its credibility as Ukrainian forces make progress in their counteroffensive with the help of aid from Western countries.