
Russian President Vladimir Putin gestures while speaking during a media conference after a G-8 summit at the Lough Erne golf resort in Enniskillen, Northern Ireland, on Tuesday, June 18, 2013. (Associated Press)

Russian President Vladimir Putin gestures while speaking during a media conference after a G-8 summit at the Lough Erne golf resort in Enniskillen, Northern Ireland, on Tuesday, June 18, 2013. (Associated Press)

Russian President Vladimir Putin, left, looks toward British Prime Minister David Cameron, center, and U.S. President Barack Obama during group photo with G-8 leaders on Tuesday, June 18, 2013, in Enniskillen, Northern Ireland. (AP Photo/Evan Vucci)

** FILE ** President Obama (center) reacts as the sun comes out as he and British Prime Minister David Cameron (left) help students as they work on a school project about the G-8 summit during a visit to the Enniskillen Integrated Primary School in Enniskillen, Northern Ireland, on June 17, 2013. The visit took place before leaders from the G-8 nations were to gather to discuss the ongoing conflict in Syria and free-trade issues. (Associated Press)

President Barack Obama meets with Russian President Vladimir Putin in Enniskillen, Northern Ireland, Monday, June 17, 2013. Obama and Putin discussed the ongoing conflict in Syria during their bilateral meeting. (AP Photo/Evan Vucci)

President Barack Obama meets with Russian President Vladimir Putin in Enniskillen, Northern Ireland, Monday, June 17, 2013. Obama and Putin discussed the ongoing conflict in Syria during their bilateral meeting. (AP Photo/Evan Vucci)

President Obama (center) reacts as the sun comes out as he and British Prime Minister David Cameron (left) help students as they work on a school project about the G-8 summit during a visit to the Enniskillen Integrated Primary School in Enniskillen, Northern Ireland, on June 17, 2013. The visit takes place before leaders from the G-8 nations are to gather to discuss the ongoing conflict in Syria and free-trade issues. (Associated Press)

** FILE ** President Obama (center) reacts as the sun comes out as he and British Prime Minister David Cameron (left) help students as they work on a school project about the G-8 summit during a visit to the Enniskillen Integrated Primary School in Enniskillen, Northern Ireland, on June 17, 2013. The visit took place before leaders from the G-8 nations were to gather to discuss the ongoing conflict in Syria and free-trade issues. (Associated Press)

U.S. President Barack Obama delivers a keynote address ahead of the G-8 summit at Waterfront Hall in Belfast, Northern Ireland on Monday, June 17, 2013. (AP Photo/ Paul Faith, Pool)