Poland’s President Andrzej Duda said Wednesday that there is an "indication" the missile that landed in Polish territory and killed two was an "air defense missile."

"There is no indication that this was an intentional attack on Poland," he said. "There are many indications that it was an air defense missile that unfortunately fell on Polish territory."

BIDEN SAYS MISSILE KILLING 2 PEOPLE IN POLAND WAS 'UNLIKELY' FIRED FROM RUSSIA IN 'MINDS OF THE TRAJECTORY' Duda said the missile was most likely a Russian-made S-300 rocket but added that officials have "no proof at the moment that it was a missile fired by the Russian side." The Polish president’s comments are the most definitive yet issued by a NATO leader after President Biden on Tuesday told reporters that it was "unlikely" that Russia fired the missile. "There is preliminary information that contests that. I don't want to say that until we completely investigate – It's unlikely in the minds of the trajectory that it was fired from Russia," Biden said. "But we'll see." POLISH PRESIDENT ANDRZEJ DUDA VERIFIES 'PREMISES' OF NATO ARTICLE 4, SPOKE WITH JENS STOLTENBERG Biden vowed to "make sure we find out exactly what happened." The missile came down Tuesday on the Polish-Ukrainian border and landed in the village of Przewodów around 3:40 p.m. Three anonymous U.S. officials told the that preliminary assessments suggested the missile was fired by Ukrainian forces at an incoming Russian one. One official first told the publication that Russian missiles crossed into NATO territory before crashing into Poland’s eastern countryside. CLICK HERE TO GET THE WHD News APP NATO officials scrambled to investigate what happened and on Wednesday the Kremlin denounced Poland’s and other countries’ reaction to the incident as "hysterical." Though in rare praise for the U.S., Russia championed the "restrained and much more professional" reaction of the U.S. NATO Secretary General Jens Stoltenberg also confirmed Wednesday that the missile that hit Poland was likely a Ukrainian air defense missile. "This is not Ukraine's fault," he told reporters. "Russia bears reasonability for what happened yesterday because this is a direct result for the ongoing war." "Ukraine has the right to shoot down those missiles that target Ukrainian cities," he added. The contributed to this report.