President Joe Biden denied on Thursday that the missile that killed two in Poland was not Ukrainian, disputing a claim made by Ukrainian President Volodymyr Zelenskyy.

Zelenskyy claimed Wednesday on Ukrainian TV that his top military commanders had informed him the missile was not Ukrainian, saying he has “no doubt” that “it was not our missile and not our missile strike,” according to Financial Times reporter Christopher Miller.

Zelensky live on state TV now refutes Western leaders’ statements and prelim evidence that missile which killed two in Poland was Ukrainian. “I have no doubt that it was not our missile or our missile strike. We have to participate in the investigation.” https://t.co/b35OmPnVqX

— Christopher Miller (@ChristopherJM) November 16, 2022

Biden was pressed about the validity of Zelenskyy’s claim as he was walking into the White House across the South Lawn at 12:30 a.m.

“That’s not the evidence,” Biden said.

Zelenskyy had also called for “action” on Tuesday after the explosion, claiming that Russian missiles had hit Poland mere miles away from the Ukrainian border.

National security adviser Jake Sullivan quickly called Zelenskyy’s office after those remarks, urging the Ukrainian president to be more careful with what he says, CNN reported, citing sources familiar.

World leaders conducted an emergency meeting in the hours after the explosion Tuesday, deliberating about the evidence and deciding how to react to a NATO country being hit by a missile for the first time in the Russia-Ukraine war. Some Ukrainian officials initially called for the need to invoke Article 5, which states that NATO allies must respond when one member state is attacked. (RELATED: Biden Holds Emergency Meeting After Missile Reportedly Strikes Poland)

After investigation, Polish President Andrzej Duda said Tuesday the missile was likely the result of a Ukrainian air defense strike targeting incoming Russian attacks. A Wednesday NATO statement backed Duda’s statement, saying the explosion was likely caused by a “Ukrainian air defense missile,” but that it’s ultimately Russia’s fault.

“Our preliminary analysis suggests that the incident was likely caused by a Ukrainian air defence missile fired to defend Ukrainian territory against Russian cruise missile attacks. But let me clear: this is not Ukraine’s fault. Russia bears ultimate responsibility as it continues its illegal war against Ukraine,” NATO Secretary General Jens Stoltenberg said in the statement.

Biden said Wednesday that the missile “unlikely” came from Russia based on “preliminary information.”

“I don’t want to say that until we completely investigate it. But it is unlikely…that it was fired from Russia,” Biden said while speaking from Bali, Indonesia.

A statement from the National Security Council (NSC) on Wednesday said they have seen “nothing” that contradicts Duda’s assessment that the missile was likely Ukrainian, but that the responsible party is Russia.

“Whatever the final conclusions may be, it is clear that the party ultimately responsible for this tragic incident is Russia, which launched a barrage of missiles on Ukraine specifically intended to target civilian infrastructure,” the NSC statement said. “Ukraine had — and has — every right to defend itself.”