President Bush has acknowledged that the five-decade Soviet rule in the Baltics after World War II was an occupation.
Latvian officials say President Bush wrote in a letter to the Latvian president Vaira Vike-Freiberga that the end of the war meant liberation for Western Europe, but the start of Soviet occupation for Estonia, Latvia and Lithuania.
On Saturday, President Bush meets in the Latvian capital, Riga, with the presidents of the three Baltic countries.
Monday, Mr. Bush will attend ceremonies in Moscow marking the end of the war in Europe, an event the Estonian and Lithuanian presidents have refused to attend.
Russian officials insist that Soviet troops liberated the Baltics from the Nazis, and were not an occupying force.
U.S. National Security Adviser Stephen Hadley, briefing reporters about Mr. Bush's trip, said Wednesday it is important to acknowledge the past in the Baltics, but also to look forward.
Some information for this report provided by AFP, AP and Reuters.