"The death of two Polish citizens made us realize just how close the war is," Morawiecki said in an op-ed piece published by Polish tabloid Super Express on Tuesday.
He added: "Putin has been terrorizing Ukraine for months now. Russian missile attacks are aimed not at military targets, but at civilian targets. Bombs are falling near Poland's borders."
Morawiecki said that Poland "was not directly attacked," according to findings by Polish and allied experts, with intelligence data showing that "it was a tragic accident."
Morawiecki also wrote in his piece that "Ukrainian air defense missiles fell on Polish soil" because "the technology failed," although he said the exact causes of the incident "are still being clarified."
“But the bottom line is that this would never have happened if it hadn't been for the war, if it hadn't been for the massive shelling of Ukraine," he said, adding that Russia "is the only party that is responsible for this tragedy."
Morawiecki insisted that Poland "is safe" and that it "does not want a war with Russia."
He argued: “There is only one way to avoid it: by supporting a Ukrainian victory."
Putin "has demonstrated that he is a ruthless politician who will stop at nothing," Morawiecki wrote.
"If Kyiv falls, Russia will direct its aggression at Poland," the Polish prime minister warned.
Morawiecki told parliament in Warsaw last week that it could not be ruled out that the missile incident was the result of a "provocation" by Russia.
Poland's President Andrzej Duda said last Thursday that the missile strike, which killed two people in a village in the southeast of his country on November 15, was "a tragic accident" that was caused by Russia's war in neighbouring Ukraine.
Two Polish citizens died when "a Russia-made missile" caused an explosion outside the southeastern Polish village of Przewodów, about 6 kilometres from the Ukrainian border, at around 3:40 p.m. on Tuesday, November 15, according to a statement by the Polish foreign ministry.
The explosion at a grain facility in Przewodów came as Russia fired dozens of missiles against cities across Ukraine in a new wave of attacks targeting critical energy infrastructure, according to officials.
“Nobody wanted to hurt anyone in Poland,” Duda said on Thursday during a visit to the site of the blast.
US Secretary of Defense Lloyd Austin said last week that the deadly explosion in Poland near its border with Ukraine was the result of a Ukrainian air defense missile that landed in Poland, but added that Russia "bears ultimate responsibility" for the incident.
NATO Secretary-General Jens Stoltenberg said last week that the missile was probably a stray fired by Ukraine's air defences and not a Russian strike, but added that Russia "bears ultimate responsibility" for the incident as it "continues its illegal war" against Ukraine.