In answer to international criticism and sanctions against its actions, Russia has flexed its military might close to Western borders.
It plans to fly long-range bombers into the Gulf of Mexico and shore up its forces around U.S. coastal borders.
That has raised Washington's hackles, which says no security concerns warrant such maneuvers.
Obama, who focused almost solely on Asia, also threw out a new line of criticism to Moscow in his speech, saying the United States was leading the efforts "opposing Russia's aggression against Ukraine, which is a threat to the world, which we saw in the appalling shoot-down of MH17."
Australia's Prime Minister Tony Abbott has taken Putin to task over the downing of the plane over Ukraine's pro-Russian break-away region bordering on Russia, saying Moscow owns some of the responsibility.