Speaking in Brussels during a European summit, Tusk said the preliminary report was "unacceptable" and some of its findings contradicted Polish information and the Chicago Convention rules on aviation investigations, Poland Radio reported.
Poland sent its findings on the Russian Interstate Aviation Committee's report to Moscow Thursday. Russian investigators were supposed to take Poland's findings into account before issuing a final report.
Meanwhile, Warsaw prosecutors are investigating suspicions vital evidence was destroyed by the Russians, Poland Radio said.
Rafal Rogalski, a lawyer representing some the 96 victims' families, told prosecutors the wreckage is being destroyed, citing a television report showing Russians cutting it into smaller pieces.
Poland has repeatedly asked Russia to protect the evidence, but it was only in October that the plane was fenced off and covered with tarpaulin.
The aged Tu-154 crashed after hitting trees in thick fog April 10. The Polish delegation was on its way to a commemoration of the 1940 Katyn Forest massacre, in which more than 20,000 Polish officers were slain by Soviet secret police.