WASHINGTON - The United States needs to increase the number of military exercises and training programs across Europe and strengthen NATO's intelligence sharing to better counter Russian aggression in the region, Defense Secretary Ash Carter said Friday after a lengthy, closed-door meeting in Germany with top American defense and diplomatic leaders.

He acknowledged that the current international economic sanctions against Russia haven't stopped Moscow's military support for rebel separatists in Ukraine.

Carter also said the U.S. and others are worried President Vladimir Putin would use similar tactics elsewhere in the region and is positioning Russia as a U.S. adversary.

"There are other things we need to be doing in recognition of the fact that, at the moment at least, Vladimir Putin does not seem to be reversing course," Carter told reporters traveling with him shortly after leaving the meeting. "Therefore we need to adapt, in a long-term sense, to that reality." (AP)