Poland's president departed Tuesday for Georgia on a joint visit with the leaders of four ex-Soviet republics that he said was meant to send a signal of solidarity with Tbilisi.
The five leaders plan to meet with Georgian President Mikhail Saakashvili.
President Lech Kaczynski left Warsaw in a government plane along with his counterparts from Lithuania and Estonia. The plane will stop in Kiev to pick up Ukrainian President Viktor Yushchenko, while Latvia's president will join the group in Georgia's capital.
"This means the solidarity of five states with the nation that has fallen victim to aggression," Kaczynski told reporters.
"We may say that the Russian state has once again shown its face, its true face," he added. "We are saddened by that but we must accept the facts of life."
Still, Kaczynski greeted as "good news" the announcement that Russian President Dmitry Medvedev has ordered a halt to military action in Georgia.
Kaczynski's office said that he discussed the plan to visit Tbilisi late Monday in a phone conversation with U.S. President George W. Bush, and that Bush expressed full support for the mission.
Poland and other former Soviet satellites have expressed deep anxiety that the escalation of fighting between Russia and Georgia signals a resurgent Russian willingness to use force to dominate the region.
Kaczynski and the presidents of the three Baltic states - Lithuania, Latvia and Estonia - issued a joint statement after the fighting broke out calling Russia's policy "imperialist and revisionist." They also called on NATO and the European Union to stand up to Moscow.
The shooter freely entered the building of the university and opened fire at those who were present on the ground floor