MOSCOW  Russia issued a rebuke to President Bush on Thursday over the conflict in neighboring Georgia, refusing an immediate withdrawal of its troops there, affirming its support for two separatist enclaves and warning the United States to avoid doing anything that would encourage its Georgian ally to reignite hostilities.

In response, in the most pointed language yet from a Bush administration official, Defense Secretary Robert M. Gates declared that Russia’s actions now required a full reassessment of administration efforts to create “an ongoing and long-term strategic dialogue with Russia.”

At a Pentagon briefing, Mr. Gates said, “Russia’s behavior over the past week has called into question the entire premise of that dialogue and has profound implications for our security relationship going forward, both bilaterally and with NATO. If Russia does not step back from its aggressive posture and actions in Georgia, the U.S.-Russian relationship could be adversely affected for years to come.”

Image A woman holding a child stands outside the Civil Registration Center in Tbilisi, Georgia. Credit... Sergei Grits/Associated Press

Still, he ruled out the use of American military force in connection with the conflict. “I don’t see any prospect for the use of military force by the United States in this situation,” Mr. Gates said. “Clear enough?”