Defense Secretary Robert Gates said Thursday that Russia risks hurting its relationship with the U.S. for years to come if it does not scale back its aggression in Georgia.

“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,” Gates told reporters.

“The United States spent 45 years working very hard to avoid a military confrontation with Russia,” Gates said. “I see no reason to change that approach today.”

However, he noted that the Department of Defense will reevaluate “the entire gamut of our military-to-military activities with Russia” and confirmed that two joint training exercises had already been canceled.

“Starting last fall, [Secretary of State Condoleezza Rice] and I began what we hoped would be an ongoing and long-term strategic dialogue with the Russian Federation. The expectation was that our two nations, despite our differences, shared areas of common interest where we could work together as real partners,” Gates added. “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.”

Gates also discussed the military-led U.S. humanitarian mission in Georgia and stressed that the U.S. expects Russia not to interfere with the effort to bring aid to the country.

He discussed the conflict between Georgia and Russia, which battled over the breakaway province of South Ossetia last week.

Gates said Russia aggressively took an opportunity to “punish Georgia for daring to try to integrate with the West economically, and politically, and in security arrangements.” He added that Russia was trying to send a message to “all of the parts of the former Soviet Union” that are trying to move out of “the longtime Russian sphere of influence.”