President Obama is headed overseas Tuesday for the remainder of the week, making stops in Estonia and Wales.

Obama will meet with leaders from Estonia, Latvia, and Lithuania on Wednesday. Last week, Obama said part of the reason he's going to Estonia is, "to let the Estonians know that we mean what we say with respect to our treaty obligations."

At the NATO summit later this week in Wales, world leaders are expected to address the threat of ISIS and Russian aggression in Eastern Ukraine.