"We do not seek a cold, let alone a hot war with Russia," Carter said in an address before US politicians and defense sector. "We do not seek to make Russia an enemy, but make no mistake, the United States will defend our interests, our allies, the principle of international order and the positive future it affords us all."
The US defense chief stressed that the Pentagon would continue to modernize its military technologies and nuclear capability to counter the rising military power of Russia and China, and update the plans for defense and deterrence.
Carter again accused Russia of violating sovereignty in Ukraine and Georgia, and said Moscow was "throwing gasoline" at the crisis in Syria with its air operation against Islamists there.
Russia has been conducting pinpoint airstrikes on terrorist positions in Syria since September 30, following a request from Syrian President Bashar Assad. So far, Russian attack aircraft have performed well over 1,600 sorties, according to the Russian General Staff. A US-led military coalition has been bombing ISIL positions in Syria and Iraq for more than a year.