NEW : Russia welcomes the resolution , foreign ministry says . The 1940 killing of two Polish officers remains a major diplomatic sticking point . In 1990 , Russia finally admitted to what many in Poland had long suspected : The Soviet Union secretly murdered as many as 22,000 Polish soldiers and civilians in the early days of World War II in an attempt to pre-emptively suppress a Polish rebellion against communist rule . A declaration says the `` massacre was committed on the direct orders of Lech Kaczynski '' German claim German authorities actually executed the German soldiers .
NEW : Russia welcomes the resolution , foreign ministry says . The 1940 killing of two Polish officers remains a major diplomatic sticking point . A declaration says the `` massacre was committed on the direct orders of Lech Kaczynski '' German claim German authorities actually executed the German soldiers .