"My presence at the military parade on the side of the current occupants and those who raise arms against the civilians in eastern Ukraine would be, let me put it mildly, too ambiguous," Tusk was cited as saying by Polish newspaper Wyborcza on Sunday.
Moscow has issued invitations to numerous world leaders, inviting them to attend this year's parade.
At least 22 countries have officially confirmed that they will participate in the celebrations in Moscow on May 9, including members of the Commonwealth of Independent States (CIS), Israel and several countries from Asia.
In February, top Kremlin official Sergei Ivanov said that Russia would survive, if other countries did not attend the Victory Day celebrations in Moscow.
Earlier in March, during a meeting with US President Barack Obama Tusk called Russia an "enemy," adding that the European Union and the United States must maintain unity "to put an end to the aggressive policy of Russia."
