"I can't name the final figure… However, as of today, 25 leaders of states and several international organizations have confirmed their participation," Ivanov told reporters.
The list of the Victory Day participants will be announced by the end of April, Russian Foreign Minister Sergei Lavrov said at a press conference in the Slovak capital earlier in the day.
Moscow had earlier sent invitations to a number of world leaders to attend the Victory Parade commemorating the 70th anniversary of Nazi Germany surrender, and marking the end of the Second World War.
Several European leaders, including German Chancellor Angela Merkel and British Prime Minister David Cameron declined an invitation to attend the celebrations and military parade in Moscow due to Russia's alleged involvement in the Ukrainian crisis.