Poland's top officials, including Prime Minister Mateusz Morawiecki and parliamentary Speaker Elżbieta Witek, attended the gathering, which culminated in a speech given by deputy prime minister and Law and Justice leader Jarosław Kaczyński.
Speaking to crowds lining the Krakowskie Przedmieście thoroughfare in central Warsaw, Kaczyński said: "Russia has not changed and its postcommunism is as murderous as communism."
"For the first time, we have received a coherent answer [about the causes of the crash ed]," he said, referring to the Russian invasion of Ukraine launched on February 24.
"I am calling the whole of Europe to mobilize support for Ukraine," Poland's conservative leader Jarosław Kaczyński, the twin brother of late President Lech, added.
Poland on Sunday marked the 12th anniversary of the presidential plane crash in Smolensk, western Russia, with a number of commemorative ceremonies across Poland and abroad.
The entire delegation of former President Lech Kaczyński, died when the Tu-154 plane crashed in thick fog on the morning of 10 April 2010.