The ministry said the Russian side had been invited to join the project for the renovation of the museum and memorial site in Sobibor in 2013. The project, initiated by Poland, Israel, Holland and Slovakia, envisions the construction of a new memorial and establishment of appropriate infrastructure.
"Russia reacted positively to that invitation, expressed its readiness to take an active part in perpetuating the memory of the extermination camp's prisoners. We are disappointed with Warsaw's refusal to let Russia join the international project to renovate the Sobibor museum," it said.
The ministry also said Poland's refusal was "immoral in terms of historic truth".