Yushchenko urged the world never to forget Babyn Yar so that such a tragedy can never happen again.
Over two days in 1941, invading Nazis killed more than 33,000 Jewish men, women, and children in the Babyn Yar ravine near Kyiv.
Up to 100,000 more people -- Jews, Roma, and Soviet prisoners of war -- were executed there during the war.
Ukrainian and foreign dignitaries including Israeli President Moshe Katsav took part in opening of an exhibit in Kyiv dedicated to the victims of the tragedy.
Organizers said a ceremony will be held at the ravine on September 27, followed by a forum aimed at "assessing the world's moral climate."
Four presidents are scheduled to attend, together with 1,000 guests representing 41 countries.
World War II: 60 Years On
A microsite devoted to RFE/RL's coverage of the 60th anniversary of the end of World War II in May 2005.