senior u.s. defense official says they believe the russians are intent on taking the capital city of kyiv. they are intent on installing, everyone to wait and see what president biden is going to say when he speaks in just about an hour from now. >> thank you so much. more to come from the white house. in the face of this massive assault, the pentagon considering repositioning more u.s. troops further east in europe to bolster nato allies. this as we've already seen russian rockets flying through the sky as cnn's frederik pleitgen witnessed firsthand russian tanks moving toward the ukrainian border. cnn's barbara starr live at the pentagon for us now and barbara, just got an update, a briefing over there. what's the very latest? >> well, the pentagon continues to say as the biden administration says, u.s. troops will not go into ukraine or fight in ukraine. this is not their war, but we are on the cusp, potentially, of the administration announcing